Answer: C. p = p
Step-by-step explanation:
A tautology is a statement that is always true.
A. p = q
This is not always true. Counterexample: p = 1 & q = 2
B. p = q
This is the same as A (above)
C. p = p
This is ALWAYS true!
D. q = p
This is the same as A but in reverse order.
