Step 1: Understand the question.
We need Delhi Airport's rank among the busiest airports in the Asia-Pacific region in 2025, per OAG data.
Step 2: Identify the rank.
Delhi's Indira Gandhi International Airport ranked 4th in the Asia-Pacific region.
Step 3: Why.
The airport has expanded its terminals and now has four runways, handling over 70 million passengers a year.
Step 4: Rule out others.
Ranks of 10th or 15th would understate its growth as a major South Asian gateway.
Step 5: Conclude.
Delhi Airport secured the 4th position.
Answer: 4th