To arrange the airports from west to east, we need to consider their geographical locations:
- Aden is the westernmost of the listed airports.
- Mumbai is to the east of Aden, located in India.
- Beijing is further to the east of Mumbai, in China.
- Tokyo is the easternmost airport of all, located in Japan.
Thus, the correct order from west to east is: Aden, Mumbai, Beijing, and Tokyo.
The correct option is (D) iii, iv, i and ii.

A ladder of fixed length \( h \) is to be placed along the wall such that it is free to move along the height of the wall.
Based upon the above information, answer the following questions:
(iii) (b) If the foot of the ladder, whose length is 5 m, is being pulled towards the wall such that the rate of decrease of distance \( y \) is \( 2 \, \text{m/s} \), then at what rate is the height on the wall \( x \) increasing when the foot of the ladder is 3 m away from the wall?