The correct option is this: WHOEVER HELD THE STRAITS COULD MOVE SOLDIERS THROUGHOUT SOUTH EAST ASIA.
Malacca straits refers to the narrow stretch of water which lie between Malay peninsula and the island of Samtra in Indonesia. Looking at it from the political and the economic perspectives, Malacca straits is one of the most strategic and important shipping route in the world.
Sunda strait is located between the island of Java and Sumatra in Indonesia. These two straits are very important during warfare and whoever is in control of the straits will be able to move soldiers throughouts south east Asia.