A plant shows thallus level of organisation.it shows rhizoids and is haploid. It needs water to complete its life cycle because the male gametes are motile . It may belong to

Options

A. pteridopytes
B. gymnosperms
C. monocots
D. bryophytes.

Explanation

To solve the question, we need to analyze the characteristics provided and determine which group of plants they belong to. Let's break it down step by step:

### Step-by-Step Solution:

1. **Identify the Level of Organization**:
- The question states that the plant shows a "thallus level of organization." This indicates that the plant does not have a true stem, leaves, or roots but has a simple body structure known as a thallus.

**Hint**: Look for plant groups that exhibit a thallus structure.

2. **Presence of Rhizoids**:
- The plant shows rhizoids, which are root-like structures. Rhizoids are typically found in bryophytes (mosses and liverworts) and help anchor the plant to the substrate.

**Hint**: Consider which plant groups have structures that resemble roots but are not true roots.

3. **Haploid Condition**:
- The plant is described as haploid. In the plant kingdom, both algae and bryophytes can have haploid stages, but bryophytes predominantly exist in the gametophyte (haploid) stage.

**Hint**: Recall that the life cycle of bryophytes is dominated by the gametophyte stage.

4. **Need for Water for Life Cycle Completion**:
- The plant requires water to complete its life cycle because the male gametes are motile. This is a key characteristic of bryophytes, which need water for the sperm to swim to the egg for fertilization.

**Hint**: Think about which plants need water for reproduction, especially for the movement of male gametes.

5. **Motile Male Gametes**:
- The statement mentions that the male gametes are motile. This is true for bryophytes, where sperm cells swim through water to reach the egg.

**Hint**: Consider the reproductive strategies of different plant groups, especially those that involve water.

6. **Conclusion**:
- Based on all the characteristics analyzed: thallus organization, presence of rhizoids, haploid condition, need for water for reproduction, and motile male gametes, the plant in question belongs to the group **Bryophyta** (mosses and liverworts).

### Final Answer:
The plant may belong to **Bryophyta**.