<prompt> Major source of Acetyl CoA:TriglyceridesFatty acidsPyruvateAlanine  <response>: As nothing is mentioned we have to assume question is asking about fed-state. In fed-state, major source of fuel is carbohydrates followed by fats and proteins. Acetyl CoA is derived from Carbohydrates, Fats Proteins also. So in fed state major source will be Carbohydrates. Glucose forms pyruvate then it forms Acetyl CoA. So best answer here is Pyruvate. 