But how would Hall get that telegram? That would take some doing, he admitted. Then Hall remembered Mr. H., one of his trusted operatives. It was Mr. H. who had alerted MI8 to the suspicious activities of Sweden's chargé d'affaires in Mexico City, Folke Cronholm. Sharp-eyed Mr. H. had noticed that Cronholm was making frequent visits to the telegraph office, far more visits than one would expect from a representative of the Swedish government, given the limited relationship between that government and Mexico. Which inference can a reader make based on the information in the excerpt? 1. Folke Cronholm was spying for the Allied nations. 2. Folke Cronholm was a German diplomat. 3. Folke Cronholm was secretly working for the Germans. 4. Folke Cronholm was receiving many personal telegraphs.

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.

i cannot see any of the options

remember, the goal of an adjective clause is to add more information to a noun or a pronoun. as you can see from the examples above, you can add information by including a longer adjective clause or tighten up a sentence by turning the adjective clause into an adjective phrase.