2.
Consider the following relations from A to B where \( A = \{u, v, w, x, y, z\} \) and \( B = \{p, q, r, s\} \).
1. \( \{(u,p), (v,p), (w,p), (x,q), (y,q), (z,q)\} \)
2. \( \{(u,p), (v,q), (w,r), (z,s)\} \)
3. \( \{(u,s), (v,r), (w,q), (u,p), (v,q), (z,q)\} \)
4. \( \{(u,q), (v,p), (w,s), (x,r), (y,q), (z,s)\} \)
Which of the above relations are not functions?