Hi chegg, please provide a step by step solution.

A motorcycle dealership has the following parts in stock: 100 tires at a cost of $50 each, 30 batteries at a cost of $80 each and 20 helmets at a cost of $100 each. The business uses a perpetual inventory system. If 10 tires are sold for $70 each and 20 batteries are sold for $100 each, which of the following journal entry is required to record the sale?

a. Debit Sales Revenue $2,700, Credit Cash $2,700

b. Debit Sales Revenue $2,700, Credit Cash $2,700; Debit COGS $2,100, Credit Merchandise Inventory $2,100

c. Debit Cash $2,100, Credit Sales Revenue $2,100

d. Debit Cash $2,700, Credit Sales Revenue $2,700; Debit COGS $2,100, Credit Merchandise Inventory $2,100