The correct answer is (a) Patna.
National Inland Navigation Institute (NINI) is a government-funded institute located in Patna, India. It was established in 1986 with the objective of providing training and research facilities in the field of inland navigation. The institute offers a variety of courses, including diploma, degree, and postgraduate programs. It also has a research center that conducts research on various aspects of inland navigation.
The other options are incorrect. Kolkata is the capital of West Bengal and is located on the banks of the Hooghly River. Goa is a state in western India and is located on the Arabian Sea coast. Gomuk is a village in Uttarakhand and is located in the Himalayas.