This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
White fibres are present in 
Select and explain. 
A. Calf muscles, B. Extraocular muscle, C. Back muscles, D. Hip muscles
B: Extraocular muscle
Answer: B: Extraocular muscle 
Explanation: Muscles that react rapidly are composed mainly of "fast" (Type 2, white Muscle) fibres with only small numbers of the slow variety.Conversely, muscles that respond slowly but with prolonged contraction are composed mainly of "slow" fibres (Type 1, Red Muscle).Fast fibres have fewer mitochondria than do slow fibres, also because oxidative metabolism is secondary. A deficit of red myoglobin in fast muscle gives it the name white muscle.Guyton 13e pg:83