Step 1: Understanding the Concept.
This task force was an early step toward what later became the Direct Benefit Transfer (DBT) system for subsidies.
Step 2: Check the options.
Apoorva Sinha and Sangam Chitra are not names associated with heading this task force, so options B and C are wrong, and since the task force had a single head, option D is also wrong.
Step 3: Final Answer.
The task force was headed by Nandan Nilekani, who was also chairing the Unique Identification Authority of India (Aadhaar) at the time, since the subsidy transfer mechanism was closely linked to Aadhaar-based identification. Option A is correct.