Evaluate the Cylindrical Coordinate Integral $\int _ { 0 } ^ { \pi / 2 } \int _ { 9 } ^ { 18 } \int _ { 1 / r ^ { 2 } } ^ { 1 / r } \cos \theta d z r d r d \theta$

Multiple Choice

Evaluate the cylindrical coordinate integral.
- $\int _ { 0 } ^ { \pi / 2 } \int _ { 9 } ^ { 18 } \int _ { 1 / r ^ { 2 } } ^ { 1 / r } \cos \theta d z r d r d \theta$

A) $18 \pi + \ln 2$
B) $9 - \ln 2$
C) $9 \pi + \ln 2$
D) $18 - \ln 2$