Answer: The water will cool down
Step-by-step explanation:
Both the water and the metal block will reach Thermal equilibrium which is a state where neither of them will be transferring energy (heat) to the other because they are now of the same temperature.
For instance, if you put a cold can in water to warm it up, the water will keep reducing in temperature while the cold can increases in temperature until both the can and the water have the same temperature.
The same logic applies here. The metal block is cooler than the water so the water will cool down and the metal block will get more heat until both of them achieve a temperature somewhere between the temperatures that both the water and the block started off with.