Vintage Weaponry is owned and operated by a craftsman who makes replicas of historic firearms for museums, sportsmen, and collectors. He is currently producing $80$ flintlock muskets per month. Data are as follows:

Sales price per unit

Variable cost per unit

Fixed costs per month

$$720$

$$470$

$$7,750$

If Vintage expects to sell $50$ units per month, how much is his margin of safety expressed in sales revenue?

A$.$ $$8,930$

B$.$ $$22,320$

C$.$ $$13,680$

D$.$ $$36,000$