To order the airports by their geographical position from west to east, the following sequence is established:
- Aden is the westernmost airport listed.
- Mumbai, situated in India, lies to the east of Aden.
- Beijing, located in China, is positioned further east of Mumbai.
- Tokyo, in Japan, is the easternmost airport overall.
Therefore, the order from west to east is: Aden, Mumbai, Beijing, Tokyo.
The correct option is (D) iii, iv, i, ii.