The primary reason behind the failure of the Young Bengal Movement in Bengal was that it was too radical. The Young Bengal Movement was a social reform movement that emerged in the early 19th century, with the objective of bringing about social and cultural changes in Bengal. However, its radical ideas and beliefs were not widely accepted by the conservative society of that time.

Option 1: It did not appeal to educated people. This option suggests that the movement failed because it did not appeal to educated individuals. However, this is not the primary reason for its failure.

Option 2: Its economic program was not popular. This option suggests that the movement failed because its economic program was not popular. While economic programs can be influential, they were not the primary reason for the failure of the Young Bengal Movement.

Option 3: It was too radical. This option correctly identifies the primary reason for the failure of the Young Bengal Movement. The movement`s radical ideas and beliefs were too radical for the conservative society, ultimately leading to its failure.

Option 4: It did not have good leaders. This option suggests that the movement failed because it lacked good leaders. While leadership can be critical to the success of a movement, it was not the primary reason for the failure of the Young Bengal Movement