You didn't really provide us with any options? It must be noted that generally, the structure of the skeletal system also dictates its function. With that I mean that having bones and a skeletal system enables us to move more efficiently and to have the pose which we have.
Answer:
4. panel study.
Explanation:
Panel study:
Panel study is a type of longitudinal study in which subject is analyzed at certain specific intervals for long period. Means, Professor Stone's study subject are teenage women and he interviewed his subjects (teenage women) at different intervals like at pregnancy, then after the birth and finally after one year.
So, panel study is used to decipher the changes in attitude of constant subjects at typical interval over a long period.
Answer:
The minimum number of days per week you should exercise is three days