Gregorio took two tests. Find his z-score for each test. (Remember: The number of standard deviations between a score and the mean score is indicated by a z-score.) On which did he score better compared with others in his class?

Test A Test B
Gregorio's score 62 70
Mean score 80 90
Standard deviation 6 10

a. Test A: 3; Test B:2; Test A
b. Test A: -2; Test B: -3; Test A
c. Test A: -3; Test B: -2; Test B
d. Test A: -3; Test B: -2; Test A