A company that makes nails finds that it would sell 42 boxes of nails per month if they are priced at $20 per box. If the company lowers the price to $10 per box, then more people would purchase nails and the company could expect to sell 52 boxes per month. Find the equation of the line for the demand equation if x represents the number of boxes sold and y is the price of a box of nails.

A.) y = 62 + x
B.) y = 42 − x
C.) y = 42 + x
D.) y = 62 − x