Sorry, but I have to ask - Is there an official language of the WC?

Ok, I know you guys are just thrilled with all the novice questions popping up on here, but I have to ask this and I will not start any other threads on here.

Is there an official language for the WC?

For example, if a team from a French speaking country is playing a team from an Arabic speaking country and the official(s) are from a Portuguese speaking country, how or in what language do they communicate?

I know a lot of players play in different countries and a decent amount can probably speak more than 1 language. But is one language designated as the official language of a match?

Anyways, sorry if this has already been addressed elsewhere. Just curious how they do this.

TIA.