Which text represents an algorithm?

An algorithm is a step-by-step procedure or formula for solving a problem or accomplishing a task. The first choice describes a clear, structured process: shaking a bulb to determine whether it rattles, which then indicates a specific action of replacing it. This reflects the essence of an algorithm, as it provides sequential instructions and involves a conditional decision based on the outcome of the action (i.e., whether the bulb rattles or not).

In contrast, the other options do not describe a process involving steps, actions, or decision-making. The second choice is a factual statement about the properties of water and fire but does not involve any procedural steps to follow. The third option expresses an opinion or observation regarding a consequence of looking at the sun, lacking any step-wise method. The fourth choice states a maximum speed limit, which is a declarative fact rather than an algorithmic process.

Thus, the first choice successfully exemplifies the characteristics of an algorithm through its conditional action and clear structure.