An urgent matter or something that needs an immediate reaction is called Answer option

Dire
Hire
Desire

Dire

Explanation:

Lets go over what each word means.

Hire means to recieve or give a  job. For example "Fred got hired to work at Microsoft"

This defnatly does not seem to be a urgent matter.

Desire means to really want something. For example "Bobs desire was to get the blue bunny at the store"

Lastly we have Dire.

This means something extreme or desprate. For example "It was dire that Anna got to the grocery store before it closed"

This can also be used as a word to describe something urgent. For example:

It was dire that Joseph got to the conference on time

So the answer is Dire

Hope this helps!

the answer is

a) revise existing treaties

b) do away with political alliances

c) prevent the spread of communism

d) bring an end to european colonization

the main goal of the southeast asia treaty organization was to prevent the spread of communism in southeast asia.