A technical supervisor has the authority to __________ the certification of any operator under their supervision.

The choice of "suspend" accurately reflects the authority that a technical supervisor has regarding the certification of operators. Suspending someone's certification can occur for various reasons, such as a violation of protocol, safety concerns, or any issues that arise during the operator’s performance. This temporary measure allows for a review of the operator’s actions and provides an opportunity for corrective actions to be taken without permanently affecting their certification status.

The other options, while related to certification, do not fit the context of the supervisor's authority as directly. For example, "revoke" implies a permanent removal of certification, which typically requires a more formal process and justification. "Grant" refers to the initial award of certification rather than oversight of existing certifications. "Restore" suggests bringing back a certification that was previously revoked or suspended, which is not part of the regular supervisory authority. Thus, "suspend" is the most appropriate term in this context, as it emphasizes the temporary and review-oriented nature of the technical supervisor's role.