Use indirect truth tables to determine whether the following argument is valid. If the argument is invalid, choose an option which presents a counterexample. (There may be other counterexamples as well.)
A ⊃ (~B ≡ C)
B ≡ D
~C ≡ ~D / ~A
(A)Valid (B)Invalid. Counterexample when A, B, and D are true and C is false (C)Invalid. Counterexample when A and B are true and C and D are false (D)Invalid. Counterexample when A, C, and D are true and B is false
A