The phrase primary health care is most strongly tied to one landmark event, so the task is to recall who first set out the concept on a world stage.
That event was the 1978 Alma-Ata conference jointly held by the WHO and UNICEF. It produced the Alma-Ata Declaration, which both defined primary health care and gave the world the target of Health for All by the year 2000. It also listed the core elements like maternal and child health, immunisation, safe water and essential drugs.
The Indian committees in the options have their own roles. Bhore in 1946 shaped the rural health service tiers, and Shrivastava in 1975 pushed for village health workers. National Health Policy statements build on the Alma-Ata idea rather than create it. So none of them is the origin of the concept.
\[\boxed{\text{Alma-Ata Declaration}}\]