The P and V operations on counting semaphores, where s is

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The P and V operations on counting semaphores, where s is a counting semaphore, and defined as follows P(s): s = s – 1;
if s < 0 then wait;
V(s): s = s + 1;
if s < = 0 then we ke up a process waiting on s;
Assume that P_b and V_b the wait and signal operations on binary semaphores are provided. Two binary semaphores X_b and Y_b are used to implement the semaphore operations P(s) and V(s) as follows
P(s): P_b (X_b);
s = s – 1;
if (s < 0) {
V_b (X_b);
P_b (Y_b);
}
else V_b (X_b);
V(s): P_b (Y_b);
s = s + 1;
if (s < = 0) V_b (Y_b);
V_b (X_b);
The initial values of X_b and Y_b are respectively

1. 0 and 0
2. 0 and 1
3. 1 and 0
4. 1 and 1

Correct Option: C

From the given code we get that P(S) and V(S), decrement and increment the value of semaphore respectively. So, from the given conditions we conclude that to avoid mutual exclusion in the value of X_b should be 1 and that of Y_b should be 0.