How many rounds of TCA Cycle would a complete oxidation of a triacyl(15-Carbon fatty acid)-glycerol, give?
I am not too sure but this is my logic:

There would be in total of 18 molecules of Acetyl-CoA which means 18 TCA cycles. Propionyl-CoA gets converted to Succinyl-CoA which is a TCA intermediate (at about half of the cycle). If you do consider this, the 3 molecules of propionyl-CoA would only give you 3 partial rounds (or lets assume 1.5 rounds) of TCA cycle. Still 19.5; less than 22. Even if you consider the metabolism of glycerol, then 1 molecule of glycerol will give you 1 molecule of pyruvate i.e. 1 TCA cycle. So, the total is still 20.5 rounds i.e. less than 22.

I don't know what the other options are but "more than 22" is certainly not correct.