the answer's a lemon
old-fashioned A derisive or dismissive answer to a question that is impertinent, foolish, or ridiculous. Primarily heard in UK. A: "The government is in service of us, so why should we have to pay taxes to them?" B: "The answer's a lemon—maybe the next time you have a thought, keep it to yourself."
the answer's a lemon
the response or outcome is unsatisfactory. informal A lemon here is used to represent a bad, unsatisfactory, or disappointing thing, possibly because the lemon is the least valuable symbol that can be achieved by playing a fruit machine.