Step 1: Associate the quote.
In \textit{The Interpretation of Dreams} (1900), Sigmund Freud argued dreams reveal disguised wishes and conflicts, giving privileged access to the \textit{unconscious}.
Step 2: Exclude others.
Watson (behaviorism) minimized internal mental states; Pavlov (classical conditioning) studied reflexes, not dream symbolism.
Step 3: Conclude.
\[
\boxed{\text{Freud (Option A).}}
\]