The correct answer is (a) Master node is sending data to a slave
The explanation: There may be four potential modes of operation for a given bus device, although most devices only use a single role and its two modes:
-> Master transmit – Master node is sending data to a slave
-> Maser receive – Master node is receiving data from slave
-> Slave transmit – lave node is transmitting data to master
-> Slave receive – Slave node is sending data to master.