Processing speed is measured in hertz (Hz), which is the number of cycles per second that a processor can perform. The higher the hertz, the faster the processing speed. There are different units of hertz, such as megahertz (MHz), which is one million hertz, and gigahertz (GHz), which is one billion hertz. Therefore,
3.4MHz is the slowest processing speed among the given options, as it is equivalent to 3.4 million hertz.
2.6GHz is equivalent to 2.6 billion hertz, which is the fastest processing speed among the given options.
5000Kbps and 4Mbps are not units of processing speed, but units of data transfer rate, which measure how much data can be transmitted over a network in a given time. Kbps stands for kilobits per second, and Mbps stands for megabits per second. One megabit is equal to 1000 kilobits, so 4Mbps is equivalent to
4000Kbps. References: The Official CompTIA IT Fundamentals (ITF+) Student Guide (Exam FC0-U61), Chapter 1: IT Fundamentals