When multiple t tests are performed,which of the following is TRUE?

A) There is a 10% chance of committing a Type I error.
B) The risk of Type I error is not impacted.
C) The risk of Type I error decreases.
D) The risk of Type I error increases.

When multiple t tests are performed, the risk of Type I error increases. This is because the more tests conducted, the more likely it is that at least one of them will yield a false positive result by chance alone. This is known as the multiple comparisons problem. To mitigate this risk, techniques such as Bonferroni correction can be employed.