Which of the following shall be a compound proposition involving the propositions p, q and r, that is true when exactly two of the p, q and r are true and is false otherwise? (A) (p∨q∧˥r) ∨ (p∨q∧r) ∧ (˥p∧q∨r) (B) (p∧q∨r) ∧ (p∧q∧r) ∨ (˥q∨˥p∧˥r) (C) (p∧q∧˥r) ∨ (p∨˥q∧r) ∨ (˥p∧q∧r) (D) (p∨r∧q) ∨ (p∧q∧r) ∨ (˥p∧q∧r)