The correct answer is "letter c. malingering."
Malingering is described as falsifying symptoms of mental or physical well-being of a person to achieve a certain goal, an example is that malingering a certain mental illness or physical illness may be used as a mitigating factor to reduce the sentence of a criminal or to receive special treatment in prison. It may also be used to skip school or work in the military.
Think of it this way:
DNA inside cells store all the genetic information on a person's looks, eye colour, hair colour etc. It makes them unique. The analogy of being like books in a library basically suggests that in a library there is so much information and every book is different with different knowledge... That's basically what DNA is; millions of different information things.
Answer:
Although you might have heard people talk about a gene for red hair, green eyes or other characteristics, it's important to remember that genes code for proteins, not traits. While your genetic makeup does indeed determine physical traits like eye color, hair color and so forth, your genes affect these traits indirectly by way of the proteins created via DNA.
Hopefully, this answer helped! :D