Here's a problem to solve: Which of the following best describes the purpose of the chromosomes in the nucleus of a cell?

Among the 4 following options, which is the correct answer?

- A: to store the genetic instructions needed to specify traits
 
- B: to release energy by breaking down food molecules
 
- C: to transport nutrients into and out of the cell
 
- D: to protect the cells from microorganisms
 