Explanation:

Correct option:1

To determine which number is divisible by 7, we'll check each option:

 Option 1: 3661 here Dividing 3661 by 7 gives a remainder of 0. i.e. divisible by 7.

- Option 2: 3915 here Dividing 3915 by 7 gives a remainder of 2

- Option 3: 3659 here Dividing 3659 by 7 gives a remainder of 5.

- Option 4: 3739 - Dividing 3739 by 7 gives a remainder of 1.

3661 is perfectly divisible by 7.