Final answer:
Approval-oriented swimmers demonstrated faster times in the group situation than in the individual situation. Therefore, the correct option is 1.
Step-by-step explanation:
The correct statement from the study by Sorrentino and Sheppard on the motivation of swimmers is:
1) Approval-oriented swimmers demonstrated faster times in the group situation than in the individual situation.
This means that swimmers who were motivated by seeking approval performed better when they were in a group rather than swimming individually.