Correct Answer:
D. too
The correct word is "too" because it forms the structure "too...for us to be able to," indicating an excessive degree that prevents something. "More," "so," and "as" do not fit this specific grammatical construction.
The correct word is "too" because it forms the structure "too...for us to be able to," indicating an excessive degree that prevents something. "More," "so," and "as" do not fit this specific grammatical construction.