【单选题】

Mountain climbers around the world dream about going up MountEverest (珠穆朗玛峰). It is the highest mountain in the worlD、But many people who have climbed the mountain have left waste material that is harming the environment.

A、team ofAmericans is planning the largest clean-up effort ever on MountEverest. They will make the risky trip up the mountain next month.
The team of eightAmericans will be guided by more than twenty Sherpas of Nepal (尼泊尔夏儿巴人). Their goal is to remove all the trash (废物，垃圾) they see. They will spend two months cleaning up the mountain by gathering oxygen bottles, fuel containers, batteries, drink cans and other kinds of trash. They are expected to remove at least three tons of trash in large bags.
Team leader Robert Hoffman is making his fourth trip up the mountain. He says he hopes to bringEverest to the condition it was in before the first successful climb fifty years ago. He also says he hopes the effort will influence other people to clean up the environment closer to home.
Human waste onEverest is a major concern. So the clean-up team will take along newly developed equipment to collect and treat human waste. Over the years, the waste articles have polluted the mountain. In the warm season when the ice melts, the polluted water flows to Nepali villages below.
What is probably the best title for this passage
A、A、Risky Trip Up MountEverest
B、Pollution on MountEverest
C、MountEverest—Clean-upEffort
D、Robert Hoffman and HisClean-up Team