In the given question, a statement with a single blank is given. Choose the most effective word from the given options to complete the sentence meaningfully. One has to be very _______ during the monsoons as the road becomes slippery.

'Cautious' can be used to make the sentence meaningful which means alert or be careful. The context of the statement is that of the monsoon season being a bit troublesome due to slippery roads which need to be navigated with care. 'Prepared' and 'smart' may appear to be true but we need to choose the most suitable response which in this case is 'cautious'. Hence, 'cautious' is the correct answer.