Scripts like PHP usually run in a script interpreter. Although your script lines eventually boil down to machine code instructions at no point during the execution of your script an executable version of your script exists. So answer C is false.

However it is not likely that a script interpreter will directly interpreted a script: it will go through a number of parsing phases to transform your script into something that can be digested easily by the script interpreter. This intermediate form is called byte code and if you cache it your script will not have to be parsed again. Because parsing is a relatively heavy operation there is definitely something to gain here. So answer B is correct.

Answer A and B both refer to data caching and that has nothing to do with byte code caching.