Answer:
Option B. -1
Explanation:
we have

we know that
The coefficient of a term is equal to the number that multiply the term
so
In this problem
14 is the coefficient of the a-term
-72 is the coefficient of the r-term
-1 is the coefficient of the c-term
-34 is the coefficient of the d-term
therefore
-1 is the coefficient of the c-term