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) varied with a standard deviation of 1.8
B) had pH 1.8 times that of average rainwater.
C) had pH 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.