Mary earns $5 per hour as a waitress. Last week she took home her regular earnings of $5 per hour plus $187 in tips for a total of $337. Which equation can be used to find how many hours, h, Mary worked last week?

A.
$337 = $187h + $5
B.
$337 = $5h + $187
C.
$337 = $187h - $5
D.
$337 = $5h - $187