The earliest animal to have been domesticated by man was most likely the

Options

A. horse
B. cow
C. dog
D. pig

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which animal was likely the first to be domesticated by humans among the options provided: horse, cow, dog, and pig.

2. **Evaluating the Options**:
- **Horse**: While horses were important for transportation and agriculture, they were domesticated later than some other animals.
- **Cow**: Cows were also domesticated for agricultural purposes but are not considered the first.
- **Pig**: Pigs were domesticated for food, but again, they are not the earliest.
- **Dog**: Dogs are often considered the first domesticated animal, with evidence suggesting they were domesticated before the advent of agriculture.

3. **Research and Evidence**: Zoological research indicates that dogs were likely the first animals to be domesticated by humans. This is supported by archaeological findings and studies that suggest dogs were domesticated from wolves.

4. **Conclusion**: Based on the evidence and research, the earliest animal to have been domesticated by man is most likely the **dog**.

**Final Answer**: Dog

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