Answer:
B. y = x - 2
Explanation:
The sale price (y) is $2 less than the original price (x - 2).
To test this out, if a book's original price is $10..
x = 10
Using y = x - 2 and to test out if it works, we'll plug in x = 10 to discover y.
y = 10 - 2
y = 8