Final answer:
D. Taylor found the first big puddle he stomped and splashed with glee. The run-on sentence from the provided options is 'Taylor found the first big puddle he stomped and splashed with glee,' which lacks proper punctuation or a conjunction between the clauses.
Step-by-step explanation:
The question asks us to identify which of the provided sentences is a run-on sentence. A run-on sentence is one that contains two or more independent clauses that are not correctly joined by a conjunction or punctuation. Here, the correct answer is D, which reads: 'Taylor found the first big puddle he stomped and splashed with glee.' This sentence should be split into two sentences or a conjunction should be added to connect the clauses properly.