A researcher wants to know if peoples standardized test performance is influenced by what they are wearing. They ask 16 ppl to take the SAT while wearing their best professional outfit. 6 months later...

A researcher wants to know if peoples standardized test performance is influenced by what they are wearing. They ask 16 ppl to take the SAT while wearing their best professional outfit. 6 months later they have the same 16 ppl take the SAT while wearing a bathing suit.

What test would you use and why? (z test, independent t test, single sample t test, paired samples)