Which Phrase Best Describes What Would Likely Happen During the Retreat

Multiple Choice

Which phrase best describes what would likely happen during the retreat of a valley glacier?

A) A line of stakes across the glacier would be gradually lowered to the valley floor directly beneath where they were originally placed.
B) A line of stakes across the glacier would continue to move down valley as the terminus of the glacier slowly retreated.
C) A line of stakes would retreat slowly up valley as the ice withdraws to its source region.
D) Who cares? The beer would get too warm!