Which SSL Certificate for IW server?

I am having a brain fart here.
Ordering a Thawte SSL certificate for SiteWorx site.
When it asks for Server Software, do I use:

ApacheSSl or ModSSl

FYI - I am running CentOS 4.4 and Apache version 2.0.59

Thanks

OK I am pretty sure this would be ModSSL, but need a confirmation from you guys, thanks.

ModSSL should be fine.

Thanks Socheat