An enterprise hosts its data center onsite and has outsourced the management of its key financialapplications to a service provider. Which of the following controls BEST ensures that the service provider's employees adhere to the security policies?AttSign$-$off is required on the enterprise's scurity policies for all users.B$.$ tAn indemnity clause is included in the contract with the service provider.C$.$tMandatory security awareness training is implemented for all users.D$.$ tSecurity policies should be modified to address compliance by third$-$party users.