You should take physics. According to me. As-
#Physics Chemistry Biology or Math cannot be learnt later in details .
#Whereas you can go for a crash course of computer anytime from any private centre following the syllabus.
#I believe that computer is  a subject that requires in our everyday life.
#There is a regular updating of the subject whereas PCMB occurs rarely.
#CBSE has kept Comp. As only a course.
#Even I too have taken pure science and learning computer in a private centre this year only.
#I ask you that you must take pure science if you think that you can bear it.
#But I must tell if you are unable you must take Computer Sci.           

You should take computers because it extends our fields of career choosing and nowadays many companies want people who can talk to computers by their own vision. Also physical education will not help a student unless he/she is going to a fitness related or sports related field.