Overall this depends on your strategy for the game, but I would do the following:
If the German player didn’t take Egypt and you still hold the Suez, send the fleet (maybe with the destroyer, maybe without) to the med sea (this is a major misplay of Germany though, so don’t bet on that).
Otherwise I would
Kill the Japanese transport in SZ59 with the destroyer. This slows down Japan a lot and is a very good move in 99.9% of all games.
Attack the Japanese sub with the British sub. A good Japs player will give you only one shot and submerge it, so he can attack Pearl with it. It might be an option to keep the sub to guard the transport, see below.
Move my transport from Australia (picking up one inf) via New Zealand (picking up the second inf) to SZ42, later moving it to SZ22, and then either landing troops in French Equatorial Africa, Belgian Congo, Algeria (if you don’t have Africa under control) or (if you are lucky and don’t need the troops there) in direction of France to unite with the British fleet.
the AC and the TR in SZ35 either load 2 inf from India, taking Egypt back together with the troops from T-J and the fighter (if the Axis bid went into Africa, you usually cannot take it back), or simply flee to SZ 33. Since India cannot be hold if you play Kill Germany first, you can take away troops from there.
I know that the fleet needs time to get to their destination, but: You haven’t wasted units then and you get some very strong units midgame when UK suffers from a low income.
Other options are:
If you want to hold Borneo for a turn, you can use your AC as a blocker. But because both attacks with inf each just have a 66.7% chance of succeeding (both succeed at a 44.4% chance) and because you just slow down Japan with it (which makes no big difference if you let him do what he wants later and focus on Germany) I consider it a waste of units.
- Attack the Japanese sub with your sub + a fighter and land the fighter on the US AC. This makes it harder for the Japs to kill Pearl, but they still can, so the fighter is lost.
A very interesting option which is pretty hard to play is an opening move if you try Kill Japan First (or Slow Japan since you usually win over Germany, Japan is hard to take like all island nations).
Build an IC in India turn 1. This needs to be prepared to be taken back by Russia at least once!! So make sure you have 2 tanks and if possible 1-2 fighters in Caucasus and maybe 1-2 inf in Persia. The whole strategy described shortly: UK needs to help Russia in Europe, US helps in Africa (or vice versa), Russia holds India and China at least once so US and UK can build ICs there turn 1 and later push with tanks. You will need air superiority there, US fighters and bombers are needed!
attack French Indo with the Indian inf + the fighter. You need to kill the inf and keep your fighter, killing his fighter is a bonus. This makes sure he cannot take India turn 1, this makes sure you hold India until turn 2 when you can build tanks.
If you are interested in the Slow Japan First strategy let me know and I give you more details.