What measures should be taken if a vendor is required to interface with government authorities on behalf of Infosys?

a$.$ The credentials of such a vendor should be verified before hand. Due Diligence must be conducted and red flags noted as a result must be assessed and addressed.

b$.$ A detailed written contract defining the scope of services of such vendors should be executed before commencement of the engagement.

c$.$ A copy of the Supplier Code of Conduct must be provided to all vendors for their acknowledgement and acceptance.

$$ d$.$ All the options are correct.