A primary character of chordates is

Options

A. Paired nerve cord
B. Ganglionated nerve cord
C. Dorsal tubular nerve cord
D. Solid ventral nerve cord

Answer

### Step-by-Step Solution:

1. **Understanding Chordates**: Chordates are a diverse group of animals that share certain key characteristics during at least some stage of their development.

2. **Identifying Primary Characteristics**: The primary characteristics that define chordates include:
- Presence of a notochord
- Dorsal hollow nerve cord
- Pharyngeal gill slits
- Post-anal tail

3. **Focusing on the Nerve Cord**: Among these characteristics, the dorsal hollow nerve cord is a significant feature. It is located on the dorsal side of the organism and is tubular in nature.

4. **Eliminating Incorrect Options**:
- A paired nerve cord is not a characteristic of chordates; instead, they possess a single dorsal nerve cord.
- A solid ventral nerve cord is characteristic of non-chordates, such as some invertebrates.

5. **Conclusion**: Based on the analysis, the primary character of chordates is the presence of a dorsal hollow nerve cord.

### Final Answer:
The primary character of chordates is the presence of a **dorsal hollow nerve cord**.

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