Answer:
A) International wars
Explanation:
In the 1960s the Cold War between the Warsaw Pact and NATO was raging and both the United States and the Soviet Union were scrambling for allies all over the world.
Without a treaty to protect Antarctica, it would only have been a matter of time before one of the superpowers set up a military base on the continent.
Such an occurrence would not have benefitted either nation as an arms race would have developed on the most inhospitable landmass on Earth. It would have made sense to reserve the continent for scientific reserve while also maintaining it peaceful and environmentally pristine.
water is the correct answer if you are on plato