If a store has a 20% off deal, what equation represents how to find the discount price?
a) Discount Price = Original Price × (1 - 0.20)
b) Discount Price = Original Price + (Original Price × 0.20)
c) Discount Price = Original Price ÷ (1 - 0.20)
d) Discount Price = Original Price - (Original Price × 0.20)