Select the correct statement:

Options

A. Gymnosperms are both homosporous and heterosporous
B. Salvinia, Ginkgo and Pinus all are gymnosperms
C. Sequoia is one of the tallest trees
D. The leaves of gymnosperms are not well adapted to extremes of climate

Answer

To solve the question of selecting the correct statement among the given options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Evaluate the First Statement:**
- The first statement claims that Gymnosperms are both homosporous and heterosporous.
- **Analysis:** Gymnosperms are primarily heterosporous, meaning they produce two different types of spores (microspores and megaspores). They do not produce both types of spores simultaneously, which makes the statement incorrect.

2. **Evaluate the Second Statement:**
- The second statement mentions that Salvinia, Ginkgo, and Pinus are all Gymnosperms.
- **Analysis:** Ginkgo and Pinus are indeed Gymnosperms, but Salvinia is a genus of ferns, which are classified as pteridophytes. Therefore, this statement is also incorrect.

3. **Evaluate the Third Statement:**
- The third statement asserts that Sequoia is one of the tallest trees.
- **Analysis:** This statement is correct. Sequoia trees are known for their height and are classified as Gymnosperms. Therefore, this statement is true.

4. **Evaluate the Fourth Statement:**
- The fourth statement claims that the leaves of gymnosperms are not well adapted to extremes of climate.
- **Analysis:** This statement is incorrect. Gymnosperms, particularly conifers, have adaptations such as needle-like leaves, thick cuticles, and sunken stomata that help them withstand extreme climates, including cold temperatures and dry conditions.

### Conclusion:
After evaluating all four statements, the only correct statement is the third one: **"Sequoia is one of the tallest trees."**