The pH of pure water at 25°C is 7. When measured using a given meter, the measured pH actually varies from measurement to measurement with an approximate normal distribution, with a mean measured pH of 7.0 and a standard deviation of 0.07. 99% of the measured pH values are below what reading?
a. 6.84.
b. 7.06.
c. 6.94.
d. 7.07.
e. 7.16.