Suppose that a system uses DMA for data transfer from disk controller to main memory. Which of the following is NOT correct regarding using DMA for data transfer?

Question $6$ options:

The word$-$at$-$a$-$time operation can block the CPU and other devices for a substantial period if a long burst is being transfered.

When a DML controller transfers data based on the word$-$at$-$a$-$time operation, the data transfer requires acquiring and releasing bus for every word.

The burst mode operation can block the CPU and other devices for a substantial period if a long burst is being transfered.

When a DML controller transfers data in burst mode, the data transfer is more efficient due to the less time used to acquire the bus followed by a series of word transfers and releasing the bus.