In frogs heart is myogenic i.e. it is auto regulated which means it is not under the control of neural regulation thatswhy when taken out it continues to beat for sometime.It is regulated by SAN(sino atrial node) which generates the impulse on its own so it is self excitable.

Explanation:

1. Poikilotherm:
(a) Frog is a poikilotherm.
- A poikilotherm is an organism whose body temperature varies with the temperature of its environment.
- Frogs are poikilotherms, which means their body temperature changes with the temperature of their surroundings.
- This is different from homeotherms, which can maintain a constant body temperature regardless of the environment.
- The fact that a frog's heart continues to beat even after being removed from the body is related to its poikilothermic nature.

2. Coronary circulation:
(b) Frog does not have any coronary circulation.
- Coronary circulation refers to the circulation of blood within the blood vessels that supply the heart muscle with oxygen and nutrients.
- Unlike mammals and some other vertebrates, frogs do not have a well-developed coronary circulation system.
- Instead, the frog's heart receives oxygenated blood directly from its lungs through a specialized structure called the pulmonary veins.
- This direct oxygen supply allows the frog's heart to continue beating even when it is removed from the body.

3. Myogenic nature of the heart:
(c) Heart is myogenic in nature.
- The term "myogenic" refers to the ability of the heart to generate its own electrical impulses and initiate its own contractions.
- In the case of a frog's heart, it is myogenic, meaning it can produce its own electrical signals without any external stimulation.
- This is in contrast to a neurogenic heart, which relies on signals from the nervous system to initiate contractions.
- The myogenic nature of the frog's heart allows it to continue beating even when it is removed from the body.

4. Autoexcitability of the heart:
(d) Heart is autoexcitable.
- The term "autoexcitable" refers to the ability of the heart to generate spontaneous electrical activity without any external stimulus.
- The frog's heart is autoexcitable, meaning it can generate its own electrical impulses and initiate contractions without any external input.
- This autoexcitability is a result of specialized cardiac muscle cells called pacemaker cells, which can spontaneously depolarize and generate action potentials.
- These pacemaker cells are responsible for initiating the heart's electrical activity and maintaining its rhythm even when the heart is removed from the body.

Conclusion:
The correct option is (c) only (c), as the frog's heart continues to beat when taken out of the body due to its myogenic nature and autoexcitability. The frog is a poikilotherm and does not have a well-developed coronary circulation system, but these factors are not directly related to the heart's ability to continue beating outside the body.