This is a direct continuation of the last line of the paragraph, which speaks of a leader appointing another to a position of power and sidelining everybody else. Option (a) completes the picture perfectly by following up with the information of how this leader’s (Nehru’s) dynasty continues to hold sway to this day. Option (b) can also be eliminated as it is too general and way back in time; the passage is more contemporary in nature and says that the problem began at the dawn of self-rule. Option (c) is also too abrupt. So far, the paragraph has spoken only about power vested in the hands of one leader. His unaccountability or lack of concern for voters would be another issue altogether. Option (d) seems to be in defence of a certain leader while the paragraph is about the general political scenario in the country