Question

In Uruguay, when you arrive at a small social function, you shouldn't greet everyone as a group. It is considered impolite. Instead you should:
seek out the hosts of the gathering and greet them first.

keep the eyes lowered until someone acknowlegdes you.

greet all persons in a small group individually.

sing a song when making an entrance and also when leaving.

Answer 1

The answer is: greet all persons in a small group individually.

In a small social gathering, the proximity of you and other people is extremely close (at least within the proper distance for physical contact). People in uruguay might feel that some of them are being ignored or the presence is not valued if you do not greet all persons in the group one by one.

Answer 2

greet all persons in a small group individually.