Answer: the water
Step-by-step explanation:
The thermal energy required for a substance to be heated from 25 C to 75 C is given by

where
m is the mass of the substance
Cs is the specific heat of the substance
is the increase in temperature
- For water, we have:

- for the metal, we have:

So, we see that water requires more thermal energy, because it has a larger specific heat than the metal.