The correct answer is option 4: 3 only. This means that statement 3 is the only statement that is not true about Bhagat Singh. Let`s break down each option to understand why this is the case:

Option 1: 1 and 3 - This means that statement 1 and 3 are not true. However, statement 1 is true as Bhagat Singh was indeed influenced by socialist ideas.

Option 2: 2 and 3 - This means that statement 2 and 3 are not true. Statement 2 is true because Bhagat Singh was a member of the Hindustan Socialist Republican Association.

Option 3: 2 only - This means that only statement 2 is not true. However, statement 2 is indeed true as mentioned earlier.

Option 4: 3 only - This means that only statement 3 is not true. This is the correct answer because Bhagat Singh did not throw a bomb in the Central Legislative Assembly in 1929 with the objective to kill as many people as possible.

In conclusion, the incorrect statement about Bhagat Singh is that he threw a bomb in the Central Legislative Assembly in 1929 with the objective to kill as many people as possible