A man lifts 20 tiles from the ground up to the roof of a house. The mass of each tile is $1.2\,\text{kg}$. The roof is $15\,\text{m}$ above the ground. What amount of work does the man do against gravity on the tiles while carrying them to the roof?
- A$36\,\text{J}$
- B$180\,\text{J}$
- C$360\,\text{J}$
- D$3600\,\text{J}$