Correct option A → s; B → p, r; C → p, s; D → p, r
Explanation:
Irreversible adiabatic compression
(A) Q = 0,
∴ ∆Ssurr = 0, ∆Ssystem = 0
(B) Reversible vap
∆Ssystem > 0
as gaseous Reversible, process
∴ ∆Stotal = 0
∆Ssurr < 0
(C) free expansion of ideal gas