Burst mode for the transfer is given in the question. So there is no such stealing or any alternation for bus cycles. In one shot, complete data will be sent.
32 KB/sec => So, to send 160 bytes, time taken for this transfer => 5 ms
Hence, how long device(I/O) ties up the bus =>
= 300 ns to transfer control to the I/O + send full data in one shot + 300 ns to release the bus and transfer control to processor
= 5 ms + 600 ns
= 5.0006 ms $\approx$ 5 ms