The correct answer is B. Data transmission is one way.
In simplex transmission, data is transmitted in only one direction. This means that the sender can only transmit data, and the receiver can only receive data. Simplex transmission is often used in applications where there is no need for two-way communication, such as in alarm systems or remote control devices.
Option A is incorrect because the data format does not have to be simple in simplex transmission. The data format can be any format that is supported by the sender and receiver devices.
Option C is incorrect because data can be transmitted to long distances in simplex transmission. The distance that data can be transmitted depends on the type of transmission medium and the power of the transmitter.
Option D is incorrect because not all of the above are true about simplex transmission. Only option B is true about simplex transmission.
Option E is incorrect because simplex transmission is a valid type of data transmission.