The advantage to the cell of thegradual oxidation
of glucose during cellular respiration comparedwith its combustion
to co2 and h2o in a single stepis
(a) more free energy isreleased for a given
amount of glucose oxidized.
(b) no energy is lost asheat.
(c) energy can be extracted inusable
amounts.
(d) more co2 is produced for agiven amount of
glucose oxidized.
(e) less o2 is required for a given amountof glucose
oxidized.

(c) energy can be extracted in usable  amounts.

Explanation:

Gradual oxidation of glucose ensures that ATP is slowly synthesized almost in as the same quantity as needed for cell's metabolism at a time. Rapid glucose oxidation will result in a large portion of the energy being released as heat, since cells can only store small amounts of ATP at a particular time.

Hence, gradual glucose oxidation by cells ensures that a significant amount of energy extracted during phosphorylation is usable by the cell instead of being lost to heat.

The correct option is c.