Developer Temperature in Mammographic Film Processors Should Not Vary by More

Developer temperature in mammographic film processors should not vary by more than

A) $\pm$ 0.5 $\degree$ F.
B) $\pm$ 1.0 $\degree$ F.
C) $\pm$ 2.0 $\degree$ F.
D) $\pm$ 5.0 $\degree$ F.