Here First thing is ...when process is Running then ultimately it is getting CPU cycles ...so CPU is executing the process ...now when the process is in READY State it indicate that , process is ready with all necessary arrengements and acquired the necessary Resources ..required for execution..only thing is it needed CPU cycle/Attention..So CPU can run that process also...say for ex P1 and P2...
Now P1 is running ...so its state is RUNNING ..(CPU is executing it) now P2 comes with high priority ...so CPU will execute P2 by doing Context Switch ...but before that P2 must be in READY State .
So answer should be Both Running and Ready ....
NOTE: say CPU is not able to run the Process that are in Ready state .."MULTIPROGRAMMING" Concept can never occure .. but it's possible..just because CPU is able to RUN process in ready state...