Which of the following is an interest group?

FICCI - Federation of Indian Chambers of Commerce and Industry 

The correct answer is Option 3: FICCI - Federation of Indian Chambers of Commerce and Industry

Interest groups are organizations that seek to influence public policy or government decisions in favor of their specific interests (economic, social, professional, etc.). FICCI is an interest group representing the interest of industrialists.

Let's look at the options:

1. DDA (Delhi Development Authority) – A government body, not an interest group.

2. BSP (Bahujan Samaj Party) – A political party, not an interest group.

   4. BAPS (Bochasanwasi Akshar Purushottam Swaminarayan Sanstha) – A religious and cultural organization, not an interest group in the political asense.