The Non-Cooperation Movement, led by Mahatma Gandhi, had multiple impacts on the Indian society and its struggle for freedom against the British rule.

Option 1 suggests that all four given impacts were a result of the movement. However, the IV statement isn`t entirely correct as the British government didn`t show any willingness to grant political concessions, due to the movement.

Option 2 states that the movement led to the growth of Hindu-Muslim unity (II) and the removal of fear of the British `might` (III). Both these statements are accurate. The movement, indeed, saw participation from both Hindu and Muslim communities and also helped people overcome their fear of the British, inspiring them instead to fight for their rights.

Option 3 repeats the correct statement III and adds I, which suggests that Congress became a mass movement for the first time. This statement is also correct, but it isn`t a complete answer.

Option 4 combines correct statement III with incorrect one IV, making it therefore wrong.

So, the most accurate answer is Option 2 - the Non-Cooperation Movement led to the growth of Hindu-Muslim unity and the removal of fear of the British `might`.