Which of the following causes of the Evil Quartet involves the combination loss of a coevolved plant-pollinator mutualism?

Options

A. fermentation
B. alien species invasion
C. over-exploitation
D. co-extinction

Answer

To solve the question regarding which cause of the Evil Quartet involves the combination loss of a co-evolved plant-pollinator mutualism, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Evil Quartet**: The Evil Quartet refers to four interrelated causes of biodiversity loss, which include habitat destruction, overexploitation, invasive species, and co-extinction.

2. **Identify Co-evolved Mutualism**: Co-evolved mutualism refers to a relationship between two species that have evolved together and depend on each other for survival. In this context, we are looking at plant-pollinator relationships.

3. **Recognize Co-extinction**: Co-extinction occurs when the extinction of one species leads to the extinction of another species that is dependent on it. For example, if a specific plant species goes extinct, the pollinator that relies on that plant for food may also go extinct.

4. **Apply the Concept to the Question**: The question specifically asks about the combination loss of a co-evolved plant-pollinator mutualism. This means that if one species (either the plant or the pollinator) becomes extinct, the other species that relies on it will also face extinction.

5. **Select the Correct Answer**: Based on the understanding of co-evolved mutualism and co-extinction, the correct answer to the question is option number 4, which refers to the loss of a plant-pollinator mutualism.

### Final Answer:
The cause of the Evil Quartet that involves the combination loss of a co-evolved plant-pollinator mutualism is **option number 4**.