Step 1: Look at what type of parties are named in each pair.
Every pair in the options is either two national parties or two state, that is regional, parties. Sorting them this way makes the pattern easy to spot.
Step 2: Sort the pairs.
Rashtriya Janata Dal and Lok Jan Shakti Party belong to Bihar, Indian National Lok Dal and Jan Nayak Janta Party belong to Haryana, and Rashtriya Lok Dal and Jan Satta Dal belong to Uttar Pradesh, so three pairs are all regional parties tied to one state each.
Step 3: Spot the mismatch.
The Indian National Congress and the Communist Party of India (Marxist) are recognised as national parties with presence across the country, not tied to a single state like the rest.
Step 4: Conclusion.
Since this pair breaks the regional party pattern followed by the other three, the odd one out is Indian National Congress and Communist Party of India (M), option (A).