Fill in the Blanks Below with the Part on the Operating

Short Answer

Fill in the blanks below with the part on the operating system (file manager,memory manager,device drivers,window manager,scheduler,dispatcher)that performs the activity described.
A. _______________ Places new entries in the process table
B. _______________ Performs the actual communication with I/O units
C. _______________ Maintains a record of memory allocations
D. _______________ Protects files from unauthorized access