do we use an 's in acronyms ending with S?

[panosgr]

Hello all,

I am not a native english speaker and i am a bit confused with the following ; i do have an acronym that ends with s, namely LARS and i want in text specify possesion using 's.

What is the correct form for doing so. is it :
(a) LARS' because it ends with S and does need only the apostrophe or
(b) LARS's

many thanks in advance for your reply

[abaka]

LARS's. Not LARS'. But "of (the) LARS" is better in every respect.