Healthcare spending in Sikkim is primarily funded by:

The state government
Central government schemes
Out-of-pocket payments by patients
International aid organizations

The correct answer is: a) The state government.

Sikkim is a small state in the Himalayas with a population of just over 700,000 people. The state government is responsible for providing healthcare to its citizens, and it does so through a combination of public and private hospitals and clinics. The state government also provides subsidies for essential medicines and medical procedures.

Central government schemes also play a role in funding healthcare in Sikkim. The National Health Mission (NHM) is a centrally-sponsored scheme that provides funding for primary healthcare, secondary healthcare, and tertiary healthcare. The NHM also provides funding for training and capacity building of healthcare workers.

Out-of-pocket payments by patients are another source of funding for healthcare in Sikkim. Patients are required to pay for some of the costs of their healthcare, such as consultation fees, medicines, and medical procedures. However, the state government provides subsidies for essential medicines and medical procedures, which helps to reduce the out-of-pocket costs for patients.

International aid organizations also provide some funding for healthcare in Sikkim. However, the state government is the primary source of funding for healthcare in Sikkim.