What must an umpire do if conditions make continued play impossible after rain?

When conditions make continued play impossible due to rain, the umpire is responsible for ensuring the safety of the players and the integrity of the game. In this situation, calling the game immediately is necessary to prevent any further complications, such as player injuries or damaging the playing surface. The umpire's priority is to make decisions that uphold the rules and protect everyone involved.

The other choices fail to address the urgency or seriousness of the conditions affecting play. Continuing the game despite bad weather can endanger participants, while waiting for further confirmation could lead to unnecessary delays and risks to safety. Taking a break without clear improvement in the weather would not be appropriate either, as it could prolong the situation without resolving the underlying issue. Thus, promptly calling the game is the most responsible and correct action.