Which of the following is ornithophilous

Options

A. Erythrina
B. Agave
C. Grevillea
D. All the above.

Answer

To determine which of the following is ornithophilous, we need to understand what ornithophilous means. Ornithophilous plants are those that are pollinated by birds. Let's analyze the options given:

1. **Erythrina**: This plant is known to have flowers that attract birds for pollination. Therefore, Erythrina is ornithophilous.

2. **Agave**: This plant also has characteristics that allow it to be pollinated by birds. Hence, Agave is ornithophilous as well.

3. **Grevillea**: Similar to the previous two, Grevillea has flowers that are adapted to bird pollination. Thus, Grevillea is also ornithophilous.

Now, since all three options (Erythrina, Agave, and Grevillea) are ornithophilous, the correct answer is:

**Option 4: All the above.**

### Step-by-Step Solution:
1. **Understand the term "ornithophilous"**: Recognize that it refers to plants that are pollinated by birds.
2. **Evaluate each option**:
- Check if Erythrina is pollinated by birds.
- Check if Agave is pollinated by birds.
- Check if Grevillea is pollinated by birds.
3. **Conclusion**: Since all three plants are ornithophilous, select the option that includes all of them.