a glass of water at 10 °c was kept in the open. after 10 minutes, the water became warmer. which statement is correct? a the temperature of the surrounding air was less than 10 °c. b the temperature of the surrounding air was greater than 10 °c. c the final temperature of the water was less than the final temperature of the surrounding air. d the final temperature of the water was greater than the final temperature of the surrounding air.

The correct answer is B. The surrounding air was greater than 10 degrees Celsius.

In order for the water to increase in temperature, there would have to be a heat energy exchange with a substance having a higher temperature. The glass of water takes in heat energy (endothermic) from the air surrounding it until reaching an equal temperature or equilibrium.
Because of the existence of this balance, C and D are ruled out because the final temperature would be even. Otherwise, the transfer would still be occurring and that wouldn’t be the “final” temperature.

Attached is a visual representation if that makes it clearer.

I hope this helps! :)