Explanation:

The correct option is (b) To help railway minister to keep track of punctuality of trains. The eDrishti software is an online dashboard launched by Indian Railways. Its primary purpose is to provide real-time information to the Railway Minister and senior officials regarding the punctuality of trains, freight and passenger earnings, and other operational aspects of the railway system, enabling efficient monitoring and decision-making. Option (a) is incorrect as eDrishti is specific to Railways, not a general policy monitoring tool for the Prime Minister. Options (c) and (d) are incorrect as they relate to the Ministry of Home Affairs and defense, respectively, which are outside the scope of eDrishti's function.