Pradhan Mantri Kisan Samman Nidhi (PM-KISAN) is a Central government scheme primarily benefiting:

Farmers
Women entrepreneurs
Unemployed youth
Handloom weavers

The correct answer is: a) Farmers.

Pradhan Mantri Kisan Samman Nidhi (PM-KISAN) is a Central government scheme launched on 24 February 2019 to provide income support to all landholding farmers in India. Under the scheme, farmers will be provided with an annual financial assistance of ₹6,000 in three equal installments of ₹2,000 each directly into their bank accounts. The scheme is expected to benefit over 12 crore farmers across the country.

The scheme is primarily benefiting farmers as it provides them with a direct income support. This will help them to meet their financial needs and improve their livelihood. The scheme is also expected to boost agricultural production and rural economy.

The other options are incorrect as they are not the primary beneficiaries of the scheme. Women entrepreneurs, unemployed youth, and handloom weavers are also beneficiaries of various government schemes, but they are not the primary beneficiaries of the PM-KISAN scheme.