Dry air is a mixture of nitrogen, oxygen, carbon dioxide etc.
air is a mixture of gases 78% nitrogen an 21% oxygen and other components.
Lets find the electronegativity difference between the bonded atoms;
C-H = 2.6-2.2 = 0.4
C-F = 4.0-2.6 = 1.4
F-F = 4.0-4.0 = 0
H-O = 3.4-2.2 = 1.2
Here the electronegativity difference is highest for C-F bond hence C-F bond is most polar.
The correct option would be the fact that both bonding electrons had come from the oxygen to form this chemical bond.
The other options are not true.
