Answer:
Option A
Explanation:
Key Idea Use p→q=∼p∨q
and p↔q=(∼p∨q)∧(p∨∼q)
Given, p,q→T and r,s→F
∴ a:∼(p∧∼r)∨(∼q∨s)
≡∼(T∧T)∨(F∨F)
≡∼(T)∨(F)
≡F∨F=F
and b: (p∨s)↔(q∧r)
≡(∼(p∨s)∨(q∧r))∧((p∨s)∨∼(q∧r))
∵p↔q≡(∼p∨q)∧(p∨∼q)
≡(∼(T∨F)∨(T∧F))∧((T∨F)∨∼(T∧F))
≡(F∨F)∧(T∨T)
≡F∧T≡F