I believe the answer is C.
Answer: Lipids.
Explanation:
The large carbon -hydrogen bonds(C-H) in chains of lipids makes them ideal storage of energy.
T<u>he more C-H bonds breakage, the higher protons availability from Citric acid cycle NADH and FADH2 and hydrogen atom splitting (to protons and electrons) for the electron transport chains (ETC</u>), and therefore the higher proton pumps for more ATP's synthesis in the mitochondria matrix.
In addition large number of electrons surrounding carbon atom in fatty acids than other food molecule is added factor. The transfer of these electrons to oxygen during oxidation of fatty acids releases large amount of energy (9 kilo calorie) into the cells, more than other food substances
Thrifty metabolism
Thrifty metabolism is the genetic
tendency toward efficient use of energy that results in below-average energy
requirements and increased storage of calories as fat. Thrifty metabolism
contributes to less weight lost when an obese person reduce the amount of his
calorie intake even though there is changes in metabolism.