In the following question, a sentence is divided into four parts. Rearrange these parts to form a grammatically correct and meaningful sentence.

(A) the keynote speaker's presentation

(B) engaging questions

(C) was intended to prompt

(D) from the audience.

The correct option is ACBD.

Let's analyze the given sentence parts to determine the correct logical and grammatical sequence:

1. Part (A) "the keynote speaker's presentation" serves as the main subject of the sentence.
2. Part (C) "was intended to prompt" follows the subject as the main verb phrase/predicate.
3. Part (B) "engaging questions" functions as the direct object of the verb "to prompt".
4. Part (D) "from the audience." is a prepositional phrase that modifies where the questions are coming from, completing the sentence.

Connecting these parts in the order (A) → (C) → (B) → (D) forms the coherent sentence:

"The keynote speaker's presentation was intended to prompt engaging questions from the audience."

Thus, the correct arrangement is ACBD.