A one-page proposal names the problem crisply and names the segment that has it. Asked why the company should build this year rather than three years ago, the author says the problem has always been there. Which of the assessment's questions is unanswered?

The principle — a problem that has always existed and is still unsolved usually has a reason, and the assessment makes a team say what it is.

Why the key is correct — Cagan's list includes Why now? (market window) The author's answer, that the problem has always been there, is the strongest possible signal that the window question has not been engaged: if nothing has changed, the team is proposing to succeed where others did not, without saying what is different now.

Why the others are wrong — the problem and the segment are two questions from a list of six, so answering them does not close it. Sizing is genuinely weak here as well, but the answer quoted is specifically about timing. And treating timing as a launch-plan concern moves a question that can stop the work into a document written after the work is approved.

Remember this — if the honest answer to why now is nothing has changed, that is the finding.

Sources — Marty Cagan on assessing product opportunities, Silicon Valley Product Group.