What type of remote-reading fuel quantity indicating system has several probes installed in each fuel tank?

The correct choice is the electronic fuel quantity indicating system. This type of system employs multiple probes within each fuel tank to measure fuel levels accurately. These probes typically operate with the help of capacitive or resistive sensors, which detect the level of fuel by measuring changes in electrical properties as fuel levels change.

In an electronic system, the data collected from these probes is sent to a central processing unit that interprets the information and displays it on the cockpit instruments. The advantage of using several probes is that it allows for enhanced accuracy and redundancy, ensuring the system provides reliable readings regardless of fuel tank shapes or configurations.

The other options, while they represent valid types of fuel indicating systems, do not employ multiple probes in the same manner as electronic systems do. Pneumatic systems rely on pressure differentials, mechanical systems use floats and levers, and magnetic systems utilize magnetic sensors. Each of these methods has its own advantages but does not incorporate multiple probes to detect fuel levels in the same way that electronic systems do.