Ninety Adults Are Expected to Attend a Book Signing $11 \frac { 1 } { 8 }$

Ninety adults are expected to attend a book signing. Each adult will drink 2 c of coffee. How many gallons of coffee should be prepared?

A) $11 \frac { 1 } { 8 }$ gal
B) $12 \frac { 1 } { 4 }$ gal
C) $11 \frac { 1 } { 4 }$ gal
D) $22 \frac { 1 } { 2 }$ gal
E) $45 \frac { 7 } { 4 }$ gal