Find C and D Such That the Solution Set to the System

Multiple Choice

Find C and D such that the solution set to the system is {(5,4) }. $$\begin{aligned}C x + 2 y & = 18 \\- 3 x + \mathrm { D } y & = 9\end{aligned}$$

A) C = 2; D = 6
B) C = 4; D = 5
C) C = 6; D = 2
D) C = 5; D = 4