$Q _ { d } = 100 - 5 P + 0.004 M - 5 P _ { R }$

$Q _ { d } = 100 - 5 P + 0.004 M - 5 P _ { R }$ ,where P is the price of good X, M is income, and $P _ { R }$ is the price of a related good, R.
-What is the demand function when M = $50,000 and $P _ { R }$ = $10?

A) $Q _ { d } = 350 - 5 P$
B)
$Q _ { d } = 300 - 5 P$
C) $Q _ { d } = 200 - 5 P$
D) $Q _ { \boldsymbol { d } } = 100 - 5 P$
E) none of the above