Equistem belongs to class

Options

A. Lycopsida
B. Psilopsida
C. Sphenopsida
D. Pteropsida

Answer

To determine the class to which Equistem belongs, we can follow these steps:

### Step 1: Identify the scientific classification of Equistem
Equistem, commonly known as horsetail or snake grass, is a genus of vascular plants. It is important to understand its classification within the plant kingdom.

### Step 2: Understand the characteristics of Equistem
Equistem is known for its unique features such as being a vascular plant that reproduces by spores. It is often referred to as a living fossil, indicating that it has existed for millions of years and has retained primitive characteristics.

### Step 3: Review the options provided
The options given are:
A. Lycopsida
B. Cilopsida
C. Spinopsida
D. Teropsida

### Step 4: Analyze the options
- **Lycopsida**: This class includes clubmosses and is not related to Equistem.
- **Cilopsida**: This is not a recognized class in the classification of plants.
- **Spinopsida**: This class includes horsetails and is the correct classification for Equistem.
- **Teropsida**: This class includes flowering plants and is also not related to Equistem.

### Step 5: Conclude the correct answer
Based on the analysis, Equistem belongs to the class **Spinopsida**. Therefore, the correct answer is **C. Spinopsida**.

---