Question

read the excerpt from \how we entered world war i\.
in the midst of it came the revelation of the telegram from german foreign minister arthur zimmermann inviting mexico into alliance as a belligerent. as a scheme to keep u.s. forces occupied on their own border, it offered to help mexico regain her lost territories of texas, arizona, and new mexico.
the author most likely uses the word \scheme\ to
o explain to the reader that acts of war are carefully planned and executed.
o point out the anger the united states had toward mexico and germany.
o show the reader that germany was a legitimate threat to the united states.
o demonstrate that germany had no allies in world war i.

Explanation:

The word "scheme" in the context of the text refers to a secret or underhanded plan. In this case, Germany's offer to Mexico to form an alliance as a belligerent (a country at war) and help Mexico regain lost territories of Texas, Arizona, and New Mexico is presented as a "scheme." This implies that the plan is devious or has ulterior motives. The other options do not fit the connotation of the word "scheme" as used here.

Answer:

show the reader that Germany was a legitimate threat to the United States.