Oldest gymnospermous tree is

Options

A. Taxodium mucronatum
B. Pinus longavaea
C. Zamia pygmia
D. Sequoia sempervirens.

Answer

### Step-by-Step Solution

1. **Understanding the Question**: The question asks for the oldest gymnospermous tree. Gymnosperms are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes.

2. **Analyzing the Options**: The options provided are:
- A) Taxodium Mucarnatum
- B) Pinus longavia
- C) Zamiya Pagamiya
- D) Sequoia sempervirens

3. **Researching Each Option**:
- **Taxodium Mucarnatum**: Commonly known as the Montezuma cypress, it is not known for its longevity.
- **Pinus longavia**: Known as the Western Bristlecone Pine, this species is recognized for its remarkable longevity and is considered the oldest living non-clonal tree.
- **Zamiya Pagamiya**: This species is relatively small, reaching only about 25 centimeters above ground, and is not known for its age.
- **Sequoia sempervirens**: Known as the coast redwood, it is one of the tallest trees but not the oldest.

4. **Identifying the Oldest Tree**: Among the options, **Pinus longavia** is noted for its longevity and is recognized as the oldest gymnosperm tree.

5. **Conclusion**: Therefore, the answer to the question "Oldest gymnospermous tree is?" is **B) Pinus longavia**.