Answer:
The correct answer is:
D. Migrants would not have needed special technology to cross the land.
Step-by-step explanation
:To understand this answer we need to analyze all of the options:
a) this doesn't support our land-bridge theory. Therefore, is incorrect.
b) this supports it and says that ice was not a limit for migrants to arrive in North America. However, it uses ice as a barrier, not a way to cross to North America.
c) this is against the theory, so it is incorrect.
d) This supports the theory in a very brilliant way because it says it was easy to cross the land. However, even though they crossed the ice. It is supporting it. Unlike option b) which uses ice as a barrier, not a way to cross.