A piece of gold, previously at room temperature, is placed in a water bath with a temperature of 100∘C. If we consider the gold to be the system and assume w constant, what is the outcome of this action?

a. heat flows out of the system and its internal energy decreases
b. heat flows out of the system and its internal energy increases
c. heat flows into the system and its internal energy decreases
d. heat flows into the system and its internal energy increases