To improve market access, Assam promotes the establishment of:

Farmer Producer Organizations
Self Help Groups
Krishi Vigyan Kendras
Agricultural Research Institutes

The correct answer is: a) Farmer Producer Organizations (FPO).

Farmer Producer Organizations (FPOs) are groups of farmers who come together to produce, market, and sell their products. FPOs can help farmers to improve their market access by negotiating better prices for their products, reducing costs, and improving quality control.

Self Help Groups (SHGs) are groups of people who come together to save money and access credit. SHGs can help farmers to improve their financial situation, but they do not directly improve market access.

Krishi Vigyan Kendras (KVKs) are agricultural extension centers that provide farmers with training and information on agricultural practices. KVKs can help farmers to improve their productivity, but they do not directly improve market access.

Agricultural Research Institutes (ARIs) are research centers that conduct research on agricultural issues. ARIs can help to develop new agricultural technologies, but they do not directly improve market access.

In conclusion, the correct answer is: a) Farmer Producer Organizations (FPO).