HMS, BM EQ-Bank 27 MC Which pair of muscles work together in an agonist-antagonist relationship? Deltoid and trapezius Biceps and gastrocnemius Triceps and biceps brachii Quadriceps and deltoid Show Answers Only \(C\) Show Worked Solution Consider Option C: These muscles work in direct opposition at the elbow joint – biceps flexes while triceps extends Other Options: A: Incorrect because deltoid and trapezius work in different regions and don’t form an antagonistic pair B: Incorrect because biceps and gastrocnemius work at different joints (elbow and ankle respectively) D: Incorrect because quadriceps and deltoid work at different joints (knee and shoulder respectively) \(\Rightarrow C\)