Answer:
a. Exothermic.
Explanation:
We know that there are several types of chemical reactions. In some reactions, the energy which is absorbed to break down the bonds of the reactants becomes less than the energy which is released at the time of forming new bonds of the products.
This means that in the whole reaction, energy is released as either light or light. This type of reaction is called an exothermic reaction.
Natural selection occurs to give help the best survival chance to the organisms.
We see rainbows when the son is behind us and some type of water or rain is in front of us. When the sun light hits a raindrop it's refracted and is changed in direction.
(and we see them with our eyes mannnn or womannnn)
B because B is the nucleus which is the storage location of DNA