Which of the following components can be damaged by electrical discharge?

Electrical discharge can lead to damage in all the components listed: diodes, capacitors, and transistors. When an electrical discharge occurs, such as from electrostatic discharge (ESD), it can create surges of current that exceed the component's voltage or current ratings.

For diodes, particularly, excessive current from an electrical discharge can cause overheating and thermal breakdown. Diodes are often used for rectification and when they experience discharge events, they can become permanently damaged if the current exceeds their specified limits.

Capacitors can also be vulnerable to damage from electrical discharges. If an electrical discharge causes a voltage spike, it might exceed the capacitor's rated voltage, leading to dielectric breakdown. This can cause the capacitor to short circuit or fail, often resulting in physical damage or reduced functionality.

Transistors, which are used as switches or amplifiers in circuits, are also susceptible to damage from electrical discharge. The high current levels can lead to junction overheating or breakdown, negatively affecting their performance or entirely destroying the component.

Given that all three components have the potential to be damaged due to electrical discharge, the choice indicating that all of them can be affected is accurate and reflects the vulnerability of electronic components to transient electrical events.