A Retailer Knows That $\mathrm { n }$ Games Can Be Sold in a Month If the Price

A retailer knows that $\mathrm { n }$ games can be sold in a month if the price is $20 - 0.2 \mathrm { n }$ dollars per game. If he buys each game for $\$ 10$ , and if he wishes to make a profit of at least $\$ 120$ per month on sales of this game, how many games must he sell each month?

A) $20 \leq n \leq 30$
B) $15 \leq n \leq 20$
C) $15 \leq n \leq 25$
D) $20 \leq n \leq 50$