Solve the Problem $\mathrm { f } ( \mathrm { x } ) = 1 + 1.5 \ln ( \mathrm { x } + 1 )$

Solve the problem.
-The function $\mathrm { f } ( \mathrm { x } ) = 1 + 1.5 \ln ( \mathrm { x } + 1 )$ models the average number of free-throws a basketball player can make consecutively during practice as a function of time, where $x$ is the number of consecutive days the basketball player has practiced for two hours. After 13 days of practice, what is the average number of consecutive free throws the basketball player makes?

A) 8 consecutive free throws
B) 6 consecutive free throws
C) 9 consecutive free throws
D) 5 consecutive free throws