Which sentence correctly uses a pronoun in the nominative case as a subject?
a. stefani and me stretch for thirty minutes prior to our vaulting competition.
b. prior to our vaulting competition, stefani and i stretch for thirty minutes.
c. our team stretches for thirty minutes prior to our vaulting competition.
d. their trainer requires that the team members stretch for thirty minutes prior to a vaulting com

The only sentences that use a pronoun in the nominative case as a subject are A and B, because in C, the subject is our team (so not only the pronoun), and in D, the subject is their trainer (the same case).
Since we are looking for the nominative case, we can reject A as an incorrect answer - the pronoun me is the objective case, not nominative.
This means that the correct answer is B. Prior to our vaulting competition, Stefani and I stretch for thirty minutes.

The answer is observations and interpreting.