Ethan earns $12 per hour for walking Ms. Barns's two dogs, plus an additional $7 for brushing the dogs after their walk.

→ Let x represent the hours Ethan works.
→ Let y represent the total he earns each day.

Which number sentence best represents this situation?

A. 12 + 7 + 2 = y

B. 12x · 2 + 7 = y

C. 12x + 7 = y

D. 12x - 7 = y