After 3 rounds of β-oxidation, a fatty acyl-CoA intermediate is produced which is designated 12:2Δ3,6. At this point in the process (production of a fatty acyl-CoA intermediate designated 12:2Δ3,6), which of the following is TRUE of the next enzyme-catalyzed reaction?
A) It produces NADH.
B) It produces FADH2.
C) It is an isomerization.
D) It is a hydration.