Final answer:
The proverbial saying 'to spoil the whole bunch (or barrel)' means that one bad person or thing can have a negative impact on a larger group of people or things, as seen in the 'bad apple' theory.
Step-by-step explanation:
In English, the proverbial saying 'to spoil the whole bunch (or barrel)' means that one bad person or thing can have a negative impact on a larger group of people or things. This concept is known as the 'bad apple' theory. Essentially, it suggests that the actions or behavior of one individual can ruin the reputation or affect the overall quality of a group.
For example, if one student in a classroom consistently misbehaves, it can create a disruptive and negative environment for the entire class. Similarly, if one employee in a workplace consistently performs poorly, it can affect the morale and productivity of the entire team.
So, the correct answer to the question is: a) One Bad Apple.