What do glaciers deposit that scientists study ancient climates?

plants that produce pollen grains
rocks formed from lava
sediment that contains fossils
animals that migrate

Sediment that contains fossils are the glaciers deposit that helps scientists study ancient climates. Hence the answer is option C.  

Explanation:

Glaciers are the big ice formed due to the cold weather in Arctic ocean and Antarctic ocean. These are the huge mass and very old in age. Some of them are 1000 years old. The animal which used to live at that time got trapped in The glacier and got preserved.

The body is a deposited in sediments. When the archaeologist search those glacier the sediments which contains fossils are found and they are helpful for determining the animals and their lifestyle which was extinct many years back.  

the man is bald so he has no hair to get wet

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.