Step 1: Understanding the Concept
The negation of an implication is \(\sim(p\rightarrow q)\equiv p\wedge\sim q\). So \(p\rightarrow q\) and \(p\wedge\sim q\) always have opposite truth values.
Step 2: Biconditional
A biconditional is true only when both sides have the same truth value. Here the two sides always differ, so \((p\rightarrow q)\leftrightarrow(p\wedge\sim q)\) is always false, i.e. a contradiction.
Step 3: Negate
The negation of a contradiction is always true, so \(\sim[(p\rightarrow q)\leftrightarrow(p\wedge\sim q)]\) is a tautology.
Final Answer:
The given statement is a tautology.
\[ \boxed{\text{(D) }\text{a tautology}} \]