The answer is C. Protein is what helps your hair, skin, and nails grow.
Well, It depends of what the breed is, I don't think there is an answer of how many dogs die at age 5, It varies.
C. it is substance abuse. because you are using it to take care of an issue incorrectly (at least i’m pretty sure)
The skin is the important part of the integumentary system (main part actually)