The correct options are
A India's national highway system is the second largest in the world based on length.
B National highways in India are under the control of the central government.
C They connect the major cities in India.
National highways are the roads that link important cities, like capitals of states and ports. India has the second largest national highway system based on length, after Australia. National highways are under the control of the central government, and are maintained by the National Highway Authority of India (NHAI).