Another way to work this out is to sort the four options by whether they are retributive (purely punishing) or reformative (aimed at rehabilitating the offender), since Section 4's innovation is specifically about adding a reformative option.
Since Section 4's innovation is specifically about giving courts a reformative sentencing tool, and only one of the four options fits that description, the answer is Community Service.
A further way to confirm the answer is to think about which of these four punishments matches a recognised global trend in criminal justice reform that India's new code was designed to reflect.
Since Community Service is the option consistent with the broader, internationally recognised trend toward reformative sentencing that the new code was designed to reflect, that is the correct answer under Section 4 of the BNS.