Answer:
FADH2 is a reducing agent.
FAD is an oxidizing agent.
Explanation:
The full form of FAD is flavin adenine dinucleotide. It is mainly a redox-active coenzyme which is associated with the different proteins and is involved with the enzymatic reactions in the metabolism.
FAD is obtained by donating or accepting electrons.
In the citric acid cycle,
succinate + FAD → fumarate + 
Thus we see that FAD is an oxidizing agent while
is a reducing agent.
H2(g) +C2H4(g)→C2H6(g)
H-H +H2C =CH2→H3C-Ch3
2C -H bonds and one C-C bond are formed while enthalpy change (dH) of the reaction,
H-H: 432kJ/mol
C=C: 614kJ/mol
C-C: 413 kJ/mol
C-C: 347 kJ/mol
dH is equal to sum of the energies released during the formation of new bonds or negative sign, and sum of energies required to break old bonds or positive sign.
The bond which breaks energy is positive.
432+614 =1046kJ/mol
Formation of bond energy is negative
2(413) + 347 = 1173 kJ/mol
dH reaction is -1173 + 1046 =-127kJ/mol
Some potential energy was converted into thermal energy due to friction. The acceleration due to gravity became smaller as the box slid down the ramp.
B is the right answer "right"