Final answer:
The citation phrase "For conspicuous gallantry and intrepidity in action..." belongs to the Medal of Honor, which is the highest military decoration in the US.
Step-by-step explanation:
The medal that uses "For conspicuous gallantry and intrepidity in action at the risk of life above and beyond the call of duty..." as the opening phrase in the citation is d) Medal of Honor. The Medal of Honor is the highest military decoration presented by the United States government to a member of its armed forces. The phrase you've mentioned signifies the level of heroism and bravery that is recognized by this distinguished award, and it is reserved for those who have performed an act of valor that is far beyond what is expected in battle.