Final answer:
The temperature of Beaker A starts at -12.0 °C and gradually increases until all the ice has melted, reaching 22.2 °C.
Step-by-step explanation:
The temperature of Beaker A initially starts at -12.0 °C and slowly increases as heat is absorbed by the ice, causing it to warm up. After 30 minutes, the temperature of the ice is still 0 °C because it is still melting without changing its temperature. Only after all the ice has melted does the absorbed heat cause the temperature to increase to 22.2 °C.