Fatty acids are the main source of energy for: (A) Muscles, (B) Heart, (C) Liver, (D) RBC
Answer is B. Fed state Preferred fuel
Starvation preferred fuel




RBC


Glucose
Glucose




Heart


Fatty acids
Ketone bodies




Brain


Glucose
Ketone bodies




Liver


Glucose
Fatty acids / protein




Muscle


Glucose
Fatty acids




Adipose tissue


Glucose 
Fatty acids.