Question

A large proportion of oxygen is left unused in the human blood even after its uptakes by the body tissues. This $O _{2}$ :

• A. acts as a reserve during muscular exercise
• B. raises the $PCO_2$ of blood to $75 \,mm$ of $Hg$
• C. is enough to keep oxyhaemoglobin saturation at $96\%$
• D. helps in releasing more $O_2$ to the epithelial tissues

Answer 1

Answer: (A)

acts as a reserve during muscular exercise