Hey , soo i read the question i think one of the hints is that it says ANTIsense SUT1 MRNA - The word anti just clicks to you that its opposite to the original sense SUT 1 and since opposite base sequences = complementary which then you can map out that double stranded MRNA which means that it can no longer bind to Trna to form a protein (as it’s not single stranded) soo its not translated - does that make sense?
(ps this was a slightly difficult question as i can see why you mentioned it makes a enzyme but just read the question and 1 hint or two will be there for sure)