The foreign policy powers of the president include:
- the ability to send troops into combat (subject to Congress's War Powers Resolution)
- the ability to negotiate treaties (which must be ratified by the Senate)
- the ability to approve a military intervention abroad (with the understanding that Congress may have a role)
However, the option the ability to grant a commission is not specifically a foreign policy power, as it relates more to administrative duties.
So, the best answers regarding foreign policy powers are the ability to send troops into combat and the ability to negotiate treaties. If you're looking for the most straightforward, commonly recognized powers directly associated with foreign policy, both the first and second options fit.