The correct answer is C) Float actuated limit switches. Float actuated limit switches are ideally suited for discrete-level detection, as they provide a simple on/off signal when the float reaches a specific level. This makes them well-suited for applications where you need to detect if the level has reached a certain point, rather than continuously monitoring the entire level range. The other options, such as capacitance probes (A) and differential pressure transmitters (D), are better suited for continuous-level detection, as they can provide a variable output signal that represents the entire level range. The float operated potentiometer (B) can also be used for continuous-level detection, but is less common than the other continuous-level sensor types.