Solve the Problem $27 \mathrm {~cm}$ And Dimensions $\mathrm { x } \mathrm { cm }$

Multiple Choice

Solve the problem.
-A rectangular sheet of perimeter $27 \mathrm {~cm}$ and dimensions $\mathrm { x } \mathrm { cm }$ by $\mathrm { y } \mathrm { cm }$ is to be rolled into a cylinder as shown in part (a) of the figure. What values of $x$ and $y$ give the largest volume?

A) $x = 9 \mathrm {~cm} ; y = \frac { 9 } { 2 } \mathrm {~cm}$
B) $x = 10 \mathrm {~cm} ; y = \frac { 7 } { 2 } \mathrm {~cm}$
C) $x = 8 \mathrm {~cm} ; y = \frac { 11 } { 2 } \mathrm {~cm}$
D) $x = 11 \mathrm {~cm} ; y = \frac { 5 } { 2 } \mathrm {~cm}$