The correct answer is option 'A' - Pisces Only.

Explanation:
In the animal kingdom, the heart plays a crucial role in pumping oxygenated blood to different parts of the body. However, not all animals have the same circulatory system, and some groups have different adaptations.

Pisces, which includes fish, have a two-chambered heart. This means that their heart consists of only two chambers: one atrium and one ventricle. In this type of circulatory system, the heart pumps deoxygenated blood to the gills, where it is oxygenated, and then it is distributed to the rest of the body. Oxygenated blood mixes with deoxygenated blood in the single ventricle before being pumped out to the body.

On the other hand, in amphibians, reptiles, birds, and mammals, the heart is more complex, with multiple chambers. These animals have a three-chambered or four-chambered heart. The three-chambered heart consists of two atria and one ventricle, while the four-chambered heart consists of two atria and two ventricles.

Amphibians, which include frogs and salamanders, have a three-chambered heart. The two atria receive oxygenated blood from the lungs and deoxygenated blood from the body, respectively. The single ventricle then pumps a mixture of oxygenated and deoxygenated blood to the body and lungs.

Therefore, in option 'A' - Pisces Only, the heart of fish (Pisces) does not pump oxygenated blood to different parts of the body. Instead, it pumps deoxygenated blood to the gills for oxygenation. In contrast, amphibians, reptiles, birds, and mammals have hearts that pump oxygenated blood to different parts of the body.

Pisces only
In Pisces, the heart does not pump oxygenated blood to different parts of the body. This is because Pisces have a two-chambered heart with one auricle and one ventricle. Since both the auricle and ventricle remain undivided, only deoxygenated blood passes through it
.Part 1 - Definition - Single circulation system

The type of circulatory system in which the blood passes only once through the heart in each complete circuit of the body.

First, the blood will pass through the heart to gills, then after purification, blood will be distributed to different parts of the body. Oxygenated blood will not return to the heart.

In double circulation as in mammals, heart pumps deoxygenated blood to the lungs for purification and oxygenated blood to the different parts of the body.


Part 2 - Two chambered heart

As the name suggests in a two-chambered heart, there are only two chambers: Atria (Auricle) and Ventricle.

Atria (receiving chambers) - are the first stops for blood entering the heart.

Ventricle (pumping chambers) - are the chambers that push blood out of the heart.

Animals with 2-chambered heart use gills for gaseous exchange (respiration).


Part 3 - Examples of organisms

Fishes (Pisces) have the simplest circulatory systems of the vertebrates: blood flows in one direction from the two-chambered heart to the gills and then the rest of the body.

Amphibians and Reptiles have 3-chambered heart while Birds and Mammals have 4-chambered heart. 


Part 4 - Conclusion

Fishes have a two-chambered heart which transports deoxygenated blood to gills but doesn't transport oxygenated blood to the different parts of the body.


Final step - Heart that does not pump oxygenated blood to different parts of the body is present in Pisces only.