Unprepared means caught without the readiness the moment demands. Caught unprepared, wholly unprepared, unprepared for the question.
It takes for. It covers the readiness, the skill and the kit alike, which is why it is so useful in a report: saying a team was unprepared says something went wrong before the day rather than on it.
1adjectiveunpreparedCaught without the readiness, the skill, or the kit the moment demands.
“I was completely unprepared for the exam and couldn't answer a single question.”
unprepared is a state.
From un- + prepared.
Etymology from Wiktionary, CC BY-SA