Which of these describes the United States' position on the syrian civil war

They were Allies to Syria, providing them with ammunition.

Explanation:

Syrian opposition, politically represented by the Syrian National Coalition, receives financial, logistical, political and in some cases military support from major Sunni states in the Middle East allied with the U. S., most notably Saudi Arabia, Qatar, and Turkey.

It's clearly written and stated that

US were Allies to syria