Explanation:
Before mitosis, the chromosomes are copied. They then coil up, and each chromosome looks like a letter X in the nucleus of the cell. The chromosomes now consist of two sister chromatids. Mitosis separates these chromatids, so that each new cell has a copy of every chromosome
Answer:
Energy is absorbed, so the mass is reduced.
Explanation:
The relationship between the mass and the energy is given by Einstein formula as :

m is the mass of an atom
c is the speed of light
When an atom is formed, the energy gets absorbed. As a result mass will decrease as per Einstein's equation. So, the correct option is (c) "Energy is absorbed, so the mass is reduced".
A.is an example of decomposition reaction.
Melting, of course. Just as how an ice cube melts to water.