The VO₂max of 10 Males and 10 Females Was Measured

The VO₂max of 10 males and 10 females was measured before and after a 12-week physical fitness program. What type of design would be appropriate for analyzing the resulting data?

A) 2 x 2, mixed
B) 2 x 2, within-within
C) 2 x 2 x 1, fixed
D) 2 x 2 x 1, between-between-within