What process form glaciers?

the answer is d, accumulation and compaction.

Explanation:

all of the other answer choices are examples of erosion, deposition, and weathering.

glaciers forms when snow accumulates in the same area to form ice. This accumulation makes snow to compress and recrystallize forming grains. These grains grows into larger crystals till the air pocket between them becomes very very tiny. This process of glacier formation takes more than 100 years.