A transaction schedule is serializable if its outcome (e.g., the resulting database state) is equal to the outcome of its transactions executed serially, i.e. without overlapping in time.
Seraializable is a superset of P and is equivalent to C.
Not all serializable schedules are allowed by 2PL, but all 2PL are serialisable, so S must be a superset of P.
Example S1: w1(x) w3(x) w2(y) w1(y) The lock by T1 for y must occur after w2(y), so the unlock by T1 for x must also occur after w2(y) (according to 2PL).
Because of the schedule legality, w3(x) cannot occur where shown in S1 because T1 holds the x lock at that point. However, S1 serializable (equivalent to T2, T1, T3).
So: B and C both are false according to me.
For diag and read: https://www2.cs.sfu.ca/CourseCentral/454/bzhou/documents/s7.pdf