The mitochondrial electron transport chain
a) is the site of most of the reactions of the citric acid cycle.
b) synthesizes atp.
c) pumps protons into the mitochondrial matrix during electron transport.
d) oxidizes water to 1 2 o2 and 2 h .
e) oxidizes the intermediate electron carriers, nadh and fadh2.

Option B , synthesizes ATP.

Explanation:

When the inner mitochondrial membrane is intact, ATP is synthesized. ATP is synthesized from ADP and Pi by  electrons from NADH or FADH2 to O2. This process is known as oxidative phosphorylation which is driven by an electrochemical proton gradient across the inner membrane with three processes occurring simultaneously  

a)electron transport,  

b)proton pumping, and  

c)ATP formation  

Hence, option B is correct