Read the dialogue below between Lucas and Julia:
Lucas: I’m “going to” visit my grandmother this weekend. We’ve already bought the bus tickets.
Julia: That’s nice!
Lucas: Oh no, I forgot my umbrella. It looks like it’s “going to” rain soon.
Julia: Don’t worry. “I’ll” lend you mine.
Based on the conversation, the alternative that best explains the correct use of “going to” and “will” is: