When a Wholesaler Sells N CD Players, the Revenue Is $R = 140 n - \frac { 1 } { 2 } n ^ { 2 }$

Multiple Choice

When a wholesaler sells n CD players, the revenue is $R = 140 n - \frac { 1 } { 2 } n ^ { 2 }$ . How many CD players would the wholesaler have to sell to receive $\$ 9,800$ ?

A) $170$ CD players
B) $180$ CD players
C) $140$ CD players
D) $160$ CD players
E) $150$ CD players