In my opinion spelling is a subject. I believe it is a subject because it is something you study in elementary and you will need to know it for the rest of your life.
C. Through its character’s dialogue
Answer:
From the given sentence and question, no verb is highlighted, but from the sentence, "If the speaker had been on time, the program would have begun on time", you can see that there is tautology as the word "on time" is used twice in the sentence when it could have been used only once.
Therefore, to correct this tautology, the sentence can be rewritten as: "If the speaker had been on time, the program would have begun early".
As a result of this, there is no incorrect verb form in the sentence, so it is safe to assume that the highlighted verb is correct.