In which of the following plant, pollination occurs by the act of pseudocopulation?

Options

A. Salvia
B. Opuntia
C. Ophrys
D. Aristolochia

Answer

To determine which plant undergoes pollination through the act of pseudocopulation, we can analyze the options provided:

1. **Salvia**: This plant primarily exhibits self-pollination and insect pollination, but it does not involve pseudocopulation. Instead, it relies on the attraction of pollinators through nectar and flower structure.

2. **Opuntia**: Commonly known as prickly pear, Opuntia can undergo both self-pollination and cross-pollination, typically through insect activity. However, it does not exhibit pseudocopulation.

3. **Ophrys**: This plant is known for its unique method of pollination involving pseudocopulation. The flowers of Ophrys resemble female insects in both structure and appearance, which attracts male insects. The males attempt to copulate with the flower, leading to the transfer of pollen. This process is what defines pseudocopulation.

4. **Aristolochia**: This plant generally attracts pollinators, particularly flies, but it does not involve the act of pseudocopulation.

Based on the analysis, the plant in which pollination occurs by the act of pseudocopulation is **Ophrys**.

### Solution Summary:
- **Correct Answer**: Ophrys (B orchid)
- **Reason**: Pseudocopulation occurs as male insects attempt to mate with flowers that resemble female insects, leading to effective pollination.