Which of the following (with specific heat capacity provided) would show the smallest temperature change upon gaining 200.0 J of heat?

Specific heat capacity is is the amount of heat energy required to raise the temperature of a unit mass by 1 kelvin.

Heat is given by mass * specific heat capacity * change in temperature

Hence change in temp = mc/H

In A temperature change will be (50 * 0.903) / 200 = 0.22575 °C

In B temperature change will be (50 * 0.385) / 200 = 0.09625 °C,

Therefore; 50.0 g Cu, Ccu = 0.385 J/gC, will show the smallest change in temperature.