Step 1 - Classify each pair as NATIONAL or STATE parties :
- (A) Bharatiya Janata Party and Aam Aadmi Party - both are recognised NATIONAL parties.
- (B) Indian National Lok Dal and Jananayak Janata Party - both are STATE parties of Haryana.
- (C) National People's Party and United Democratic Party - STATE parties of Meghalaya. (NPP is now recognised in the North-East region.)
- (D) Rashtriya Janata Dal and Loktantrik Samajwadi Party - STATE level parties of Bihar / Uttar Pradesh.
Step 2 - Options (B), (C) and (D) contain state/regional parties, while (A) contains national parties. Hence (A) is the odd one out.

Answer: (A) Bharatiya Janata Party & Aam Aadmi Party