Step 1: Background.
Due to alarming decline of tigers from habitat loss and poaching, India launched Project Tiger as a flagship conservation programme.
Step 2: Key fact.
The programme began in 1973 with nine tiger reserves; it later expanded and is administered by the National Tiger Conservation Authority.
Step 3: Eliminate distractors.
1975/1976 are not the official start years.
Step 4: Conclude.
\[
\boxed{\text{1973 (Option A).}}
\]