Step 1: Establishment year.
The Planning Commission was constituted by a Government of India resolution on 15 March 1950 to steer national economic planning.
Step 2: Avoid the common confusion.
1951 marks the launch of the First Five-Year Plan, not the creation of the Commission itself.
Step 3: Conclude.
\[
\boxed{\text{1950 (Option A).}}
\]