Hey sanddollarkt, thanks for submitting your question!
For this question, I'll start off by giving you the meaning to each answer choice along with the question.
Eran means they were, son means they are, era means was, and es means is.
<span>The sentence means, "What time ________ when they arrived?" </span> The answer to your question is era, the full sentence with era inserted it, <span>What time was it when they arrived?
Glad I could help! If you need anything else or have any more questions please reply to my answer and I'd love to help! Have a good one. </span>
