When Do You Use an Independent Measures T Test

When do you use an independent measures t test?

A) When you want to look at whether there are significant differences between two independent groups of participants.
B) When you want to compare scores within one group of participants, but from two conditions, all participants take part in both.
C) When you want to compare scores within two groups of participants and from two conditions, all participants take part in both.
D) When you want to look at whether there are significant relationships between two independent groups of participants.