Note: This Question Requires Access to Solver A) 3
B) 4

Note: This question requires access to Solver.
In the following linear programming problem, what is the allowable increase for the objective function coefficient for variable x?
$\begin{array} { l l } \text { Maximize } P = 3 x + 15 y \\\text { subject to } & 2 x + 4 y \leq 12 \\& 5 x + 2 y \leq 10 \\\text { and } \quad x \geq 0 , y \geq 0\end{array}$

A) 3
B) 4.5
C) 9
D) 15
E) ? (infinity)