Suppose That a Normal Model Describes the Acidity (PH) of Rainwater

Suppose that a Normal model describes the acidity (pH) of rainwater, and that water tested after
Last week's storm had a z-score of 1.8. This means that the acidity of that rain …

A) had pH 1.8 times that of average rainwater.
B) had pH of 1.8.
C) varied with a standard deviation of 1.8
D) had pH 1.8 standard deviations higher than that of average rainwater.
E) had pH 1.8 higher than avg, rainfall.