Concept:
- An odd-one-out question first requires the rule that the other options obey to be discovered, and only then the option that breaks it.
- Here the rule is about the level at which each party is recognised.
Step 1: Look for what three of the pairs have in common.
Reading down the list, pair (A) puts two all India parties together, while pairs (B) and (D) each put two regionally based parties together.
The rule, therefore, is that both parties in a pair belong to the same level of recognition.
Step 2: Recall how the two levels are defined.
A party recognised in four or more states is called a national party, while one recognised in a single state is called a state party. Recognition depends on the share of votes and the seats won.
Step 3: Apply the rule to the remaining pair.
The Nationalist Congress Party held recognition as a national party, whereas the Shiv Sena has been a state party rooted in Maharashtra. The two sit at different levels.
Step 4: Confirm that no other pair breaks the rule.
CPI(M) and BJP are both national, RJD and Janata Dal are both state level, and the United Democratic Party and the National People Party are both state parties of the north-east. Only pair (C) is mixed.
Final Answer: (C) Nationalist Congress Party & Shiv Sena