TPO 4 deer populations of the puget sound - 英檢

Paragraph 2: Nearly any kind of plant of the forest understory can be part of
a deer's diet. Where the forest inhibits the growth of grass and other meadow
plants, the black-tailed deer browses on huckleberry, salad, dogwood, and
almost any other shrub or herb. But this is fair-weather feeding. What keeps
the black-tailed deer alive in the harsher seasons of plant decay and dormancy?
One compensation for not hibernating is the built-in urge to migrate. Deer may
move from high-elevation browse areas in summer down to the lowland areas in
late fall. Even with snow on the ground, the high bushy understory is exposed;
also snow and wind bring down leafy branches of cedar, hemlock, red alder, and
other arboreal fodder.

2. It can be inferred from the discussion in paragraph 2 that winter
conditions
○ Cause some deer to hibernate
○ Make food unavailable in the highlands for deer
○ Make it easier for deer to locate understory plants
○Prevent deer from migrating during the winter

這題答案是給3
我可以理解~
只是為什摸答案不是2阿??????????????????
他們不是就是從高地移到低地嗎????

麻煩各位協助一下~
謝謝^^

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