Muscles contain a red coloured oxygen storing pigment called _______________.

The correct option is B Myoglobin

• Myoglobin is an iron- and oxygen-binding protein found in the muscle tissue of vertebrates in general and in almost all mammals.
• It is distantly related to haemoglobin which is the iron- and oxygen-binding protein in blood, specifically in the red blood cells. Hence, Muscles contain a red coloured oxygen-storing pigment called myoglobin.

So, the correct answer is 'myoglobin'.