Which of the following is not one of the three primary conditions for direct memory access to take place?

a$.$ The I$/$O device must have an internal buffer

b$.$ There must be a method to connect together the I$/0$ interface and memory There must be a means to avoid conflict between the CPU and the I$/0$ controller

C$.$

d$.$

The I$/$O controller associated with the particular device must be capable of readi and writing to memory