One year Thomas had the lowest ERA (earned-run average, mean number of runs yielded per nine innings pitched) of any male pitcher at his school, with an ERA of 2.91. Also, Karla had the lowest ERA of any female pitcher at the school with an ERA of 2.77. For the males, the mean ERA was 3.962 and the standard deviation was 0.797. For the females, the mean ERA was 4.445 and the standard deviation was 0.989. Find their respective z-scores. Which player had the better year relative to their peers? (Note: In general, the lower the ERA, the better the pitcher.)
Thomas had an ERA with a z-score of $\boxed{}$
Karla had an ERA with a z-score of $\boxed{}$
(Round to two decimal places as needed.)
Which player had a better year in comparison with their peers?
A. Karla had a better year because of a lower z-score.
B. Thomas had a better year because of a lower z-score.
C. Karla had a better year because of a higher z-score.
D. Thomas had a better year because of a higher z-score.
