Find $b$ Such That the Average Rate of Change of the Function

Multiple Choice

Find $b$ such that the average rate of change of the function $f(x)$ on the interval is equal to the given value.
- $f(x) =x^{2}+6 x+10,[3, b]$ ; average rate of change: 19

A) $b=13$
B) $b=10$
C) $b=1$
D) $b=7$