According to the PC Act, bribe accepted for doing a lawful act is:

Section 7 criminalises accepting a bribe, even for performing a lawful act, because the essence of the offence is corruptly monetising one’s official duty. The legality of the underlying act is irrelevant; once a public servant accepts any undue advantage in connection with public duty, liability arises. Options (a) and (c) are incorrect because the PC Act does not differentiate between lawful and unlawful acts when gratification is accepted. Option (d), Section 11, applies to influence over other public servants. Option (e), requiring documentation, is irrelevant. Thus, (b) is correct, reflecting the principle that corruption lies in the acceptance of undue advantage, not the legality of the act performed.