Answer: C. run-on sentence
Explanation: This is considered a run-on sentence, because it’s like having two complete sentences (independent clauses) put together but without connecting them or putting a period (after “thunder”) between them to make them into two separate sentences. So, in that sense, the idea kids of runs on and on without a comma and a conjunction word (such as “and” in this case). An example to correct this: I hear thunder, and I feel rain.
