A simple one [S]

This objective type question is said to have appeared in one of the old ISI selection papers.
A club with 'x' members is organized into 4 committees such that
[a] each member is in exactly two committees
[b] any two committees have exactly one member in common

Then,
1. exactly two values both between 4 and 8.
2. exactly one value lying between 4 and 8.
3. exactly two values between 8 and 16.
4. exactly one value between 8 and 16. [S]