Stranded on a desert island: Which 4 would you choose?

[Aerows]

59. My choice would be

Mirror, Pot (to boil water fresh water if available, but if not, can use to desalinate water by condensing steam with large leaves) and you can also reliably cook things with it, knife for obvious reasons and the first aid kit.

Mirror to signal and start fires
Pot - cook, purify water, desalinate if necessary
Knife - used to make other tools, shelter, and initially defense against predators if necessary
First Aid Kit - Antibiotics to prevent infection, and some include scalpels which include fine blades which again can be used to make fine tools (like needles to sew together thick leaves/bark to improve shelter quality, and sutures to suture wounds.

It would really depend on the geography and climate of the island, though. I'd pick the knife and the first aid kit regardless, but might make some variations on the other two. If it was extremely cold, I'd probably pick the tent to improve my chances of even making it a few days, etc.