Which of the following is an extinct species?

Options

A. Snow leopard
B. Sea mink
C. Water hyacinth
D. Lion-tailed macaque

Explanation

To determine which of the following options is an extinct species, we will analyze each option provided:

1. **Snow Leopard**:
- The snow leopard is currently classified as a vulnerable species. This means that while it is at risk, it is not extinct.

2. **Sea Mink**:
- The sea mink is known to be an extinct species. It was a marine mammal that has not been seen for many years and is no longer found in the wild.

3. **Water Hyacinth**:
- Water hyacinth is an aquatic plant that is often considered invasive, particularly in regions like Bengal. It is not extinct and is widely found in various water bodies.

4. **Lion Tailed Macaque**:
- The lion-tailed macaque is classified as an endangered species. This indicates that it is at risk of extinction but is still present in the wild.

Based on this analysis, the correct answer to the question "Which of the following is an extinct species?" is **Option B: Sea Mink**.

### Step-by-Step Solution:
1. **Identify the options**: Snow Leopard, Sea Mink, Water Hyacinth, Lion Tailed Macaque.
2. **Research each species**:
- Snow Leopard: Vulnerable species.
- Sea Mink: Extinct species.
- Water Hyacinth: Not extinct, invasive species.
- Lion Tailed Macaque: Endangered species.
3. **Determine which is extinct**: The only species that is extinct is the Sea Mink.
4. **Conclude the answer**: The correct answer is Sea Mink (Option B).