Ron wants to calculate the sales tax on two items. He is purchasing a helmet for $42 and gloves for $5.65. Sales tax is 7%. Which expression shows how Ron should calculate his total sales tax?

A
$42 + $5.65 x 7
B
$42 + $5.65 x 0.7
C
($42 + $5.65) x 0.7
D
($42 + $5.65) x 0.07