We wondered who/whom the book was about. [a] [b]

Group of answer choices

who

whom

In this sentence, "who" is the correct choice.

"We wondered who the book was about."

To determine whether to use "who" or "whom" in a sentence, you can try rephrasing the sentence and substituting "he" or "him."

In this case, the original sentence is: "We wondered who/whom the book was about."

We can rephrase it as: "The book was about ___?"

Now, let's try substituting "he" and "him":

- "The book was about he?" (sounds incorrect)
- "The book was about him?" (sounds correct)

Based on these substitutions, the correct choice in this sentence would be "whom," as it functions as the object of the sentence. Therefore, the answer is [b] "whom."