Aretailer That N Games Can Be Sold in a Month $$0 \leq n \leq 20$$

Multiple Choice

Aretailer that n games can be sold in a month at a price of 20-0.1n dollars per game. Assume that he buys each game for $13, and sells every one that he buys. if he whishes to make a profit of at least $100 per month on sales of this game, how many games must he sell each month?

A) $$0 \leq n \leq 20$$
B) $$20 \leq n \leq 50$$
C) $$20 \leq n \leq 70$$
D) $$25 \leq n \leq 35$$