In think the answer is the final one. First, it says that the dog ate a bug and then goes on to state that the exact bug the dog ate, a bee. Hope I helped.
Answer: The sentence that contains a clause used to modify the verb is the second one: "Geoff fell off the ladder into the pool because he was dizzy".
Explanation<u>:</u> <u>The sentence "Geoff fell off the ladder into the pool because he was dizzy" contains an adverb clause: "because he was dizzy".</u> An adverb clause is a dependent clause that is introduced by a subordinating conjunction. Moreover, an adverb clause generally modifies a verb. In the second sentence,<u> the adverb clause "because he was dizzy", which cannot stand alone as a sentence, is modifying the verb "fell off".</u>