Which Three of the Choices Listed Are Possible Sources for Acetyl-CoA

Multiple Choice

Which three of the choices listed are possible sources for acetyl-CoA that enters the citric acid cycle?
1. oxidative decarboxylation of pyruvate
2. β oxidation of fatty acids
3. catabolism of certain amino acids
4. citrate
5. carboxylation of pyruvate

A) 1, 2, and 3
B) 1, 2, and 4
C) 1, 2, and 5
D) 1, 4, and 4
E) 2, 4, and 5