The states of matter refer to the different forms in which matter can exist. There are four primary states of matter: solid, liquid, gas, and plasma. However, there are also two additional states of matter that are less commonly known but still recognized. Let's examine each option to determine which ones can be considered states of matter.

(i) BEC (Bose-Einstein condensate):
BEC is a state of matter that occurs at extremely low temperatures close to absolute zero. In this state, a group of atoms come together and behave as a single entity, known as a superatom. BEC is characterized by its unique quantum mechanical properties, such as wave-like behavior and the ability to exhibit interference patterns. Therefore, BEC is considered to be a distinct state of matter.

(ii) BHC (Bose-Hubbard condensate):
BHC is not a recognized state of matter. It seems to be a combination of terms, possibly referring to a hypothetical state that has not been scientifically established. Therefore, BHC is not considered to be a state of matter.

(iii) Plasma:
Plasma is the fourth state of matter, alongside solids, liquids, and gases. It is a highly ionized gas in which some or all of the electrons have been stripped away from the atoms, resulting in a mixture of positively charged ions and free electrons. Plasma is commonly found in stars, lightning, and fluorescent lights. It is considered a separate state of matter due to its unique properties and behavior.

(iv) Platelets:
Platelets are not a state of matter. Platelets are small, irregularly shaped cell fragments found in the blood that help with clotting to prevent excessive bleeding. They are not considered a state of matter as they do not possess the characteristic properties or behaviors associated with the different states of matter.

Considering the above analysis, the correct answer is option B, which includes BEC (i) and plasma (iii) as the recognized states of matter.