Two Equal Mass Objects (Which Are in Thermal Contact) Make

Two equal mass objects (which are in thermal contact) make up a system that is thermally isolated from its surroundings. One object has an initial temperature of 100°C and the other has an initial temperature of 0°C. What is the equilibrium temperature of the system, assuming that no phase changes take place for either object? (The hot object has a specific heat capacity that is three times that of the cold object.)

A) 19°C
B) 25°C
C) 23°C
D) 50°C
E) 75°C