Question

scientist alfred wegener proposed the idea that the continents were once all _____.
○ covered with jungle vegetation
○ part of one land mass
○ submerged under the ocean
○ completely flat

Explanation:

Alfred Wegener proposed the continental drift theory. This theory states that the continents were once part of a single super - continent called Pangaea. The other options (covered with jungle vegetation, submerged under the ocean, completely flat) are not part of his main continental drift hypothesis.

Answer:

part of one land mass