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

Glacial deposits  provide sufficient raw data to paleo-climatologists with regards to the climate during the pre-historic time. scientists excavate samples of these glaciers being subjected to study. these samples are specifically called "ice cores." pollen grains present in ice cores give clue to what plant species produce it when the glacial layer was just forming, during the distant past. information obtained from these pollen grains are of much importance because it provide weather element  data such as temperature and precipitation,  as well as animal species present during the period. therefore, the answer would be the first choice. 

if you are an e.dgenuity student this is wrong, i don't know the correct answer.

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