The correct answer is option (1) "1 and 2 only".

Regional Rural Banks (RRBs) and National Bank for Agriculture and Rural Development (NABARD) are the two institutions that provide direct credit assistance to rural households. RRBs were established under the provisions of the Regional Rural Banks Act, 1976, and are jointly owned by the Central Government, the concerned State Government, and the sponsor bank. They provide credit facilities to small and marginal farmers, agricultural laborers, and rural artisans. NABARD, on the other hand, is an apex development bank in India that focuses primarily on the agricultural and rural development sectors. It provides credit facilities to various institutions, including RRBs, co-operative banks, and other financial institutions, which in turn provide credit assistance to rural households.

Land Development Banks (LDBs) are also financial institutions that provide credit assistance to farmers, but they do not provide direct credit assistance to rural households. They were set up to provide long-term credit for agriculture and rural development activities such as land improvement, land development, irrigation, and farm mechanization.