Step 1: Understand the idiom "on cloud nine''
This idiom is commonly used to express a state of extreme happiness or elation.
Step 2: Context clue
Receiving a job offer is a positive event, so a happy emotion is expected.
Step 3: Eliminate incorrect meanings
- Option B: Disappointment is the opposite of the context.
- Option C and D: Confusion or tiredness are irrelevant.
Only Option A fits perfectly.