The correct answer is B. Karnal.
The Central Soil Salinity Research Institute (CSSRI) is an Indian government institute located in Karnal, Haryana. It was established in 1960 under the Indian Council of Agricultural Research (ICAR). The institute’s mandate is to conduct research on soil salinity and its management. It also provides training and extension services to farmers and other stakeholders.
The institute has a well-equipped laboratory and a field station. It also has a library and a documentation center. The institute publishes a number of research journals and bulletins.
The institute has made significant contributions to the field of soil salinity research. It has developed a number of technologies for the management of saline soils. These technologies have been adopted by farmers and other stakeholders. The institute has also trained a large number of scientists and extension workers in the field of soil salinity management.
The institute is playing a vital role in the development of agriculture in India. It is helping to improve the productivity of saline soils and to reduce the impact of salinity on the environment.
The other options are incorrect.
A. Kasaragod is a town in Kerala, India. It is not the location of the Central Soil Salinity Research Institute.
C. Gulmarg is a town in Jammu and Kashmir, India. It is not the location of the Central Soil Salinity Research Institute.
D. Gwalior is a city in Madhya Pradesh, India. It is not the location of the Central Soil Salinity Research Institute.