Which sentence uses look forward to for happy anticipation?
Hana is looking down on the crowd from the balcony.
Hana is looking up to her sister for her courage.
Hana is looking forward to seeing her sister tomorrow.✓Correct answer
Hana is looking out for her sister in the arrivals hall.
Explanation
Looking forward to seeing her sister means awaiting that reunion with pleasure. Looking up to someone expresses admiration, not happy anticipation of a future event, and it would not fit the gerund construction here.