Briefing Zend Knowledge

What is the best way to run PHP 4 and PHP 5 side-by-side on the same Apache server?

What is the best way to run PHP 4 and PHP 5 side-by-side on the same Apache server?

A.
Run one as an Apache module, the other as a CGI binary.

B.
Run both as a CGI binary.

C.
Just use .php4 for PHP4, and .php for PHP 5.

D.
Use .php for both but use different document roots.