Option (1) is incorrect: Hindu Marriage Act, 1955 applies to Jains.
Option (2) is incorrect: Hindu Marriage Act, 1955 applies to Buddhists.
Option (2) is incorrect: Hindu Marriage Act, 1955 applies to Sikhs.
Option (2) is correct: Under Section 2(2) of Hindu Marriage Act, 1955, provisions of the act shall not apply to the members of any Scheduled Tribe.