Reread the following sentence from the passage.

And after ten years spent in the heart of it, rejoicing and wondering,
bathing in its glorious floods of light, seeing the sunbursts of morning
among the icy peaks, the noonday radiance on the trees and rocks
and snow, the flush of the alpenglow.... it still seems to me above all
others the Range of Light...

From the context of this sentence, what do you conclude is the
meaning of the technical term alpenglow?

A. the enthusiasm that mountain climbers show for their hobby

B. a device similar to a flashlight, used by mountain climbers in
high, snowy areas

C. the thin air that is found at the upper range of mountains and
that causes dizziness

D. the reddish light that often appears on mountains at sunrise
and sunset