Struggle for existence and survival of the fittest theories were given by :

Options

A. Wallace
B. Darwin
C. Lamarck
D. None of these

Explanation

**Step-by-Step Solution:**

1. **Understanding the Theories**: The question asks about the theories of "Struggle for Existence" and "Survival of the Fittest." These concepts are foundational in the study of evolution and relate to how species compete for resources and adapt to their environments.

2. **Identifying Key Scientists**: The theories are closely associated with Charles Darwin, who is known for his work on natural selection and evolution. It is important to recognize that while other scientists contributed to evolutionary theory, Darwin is primarily credited with these specific concepts.

3. **Explaining the Theories**:
- **Struggle for Existence**: This theory posits that organisms compete for limited resources such as food, habitat, and mates. The competition can occur both within a species and between different species.
- **Survival of the Fittest**: This phrase, often associated with Darwin, refers to the idea that those individuals best adapted to their environment are more likely to survive and reproduce. The "fittest" are not necessarily the strongest but those most suited to their environment.

4. **Conclusion**: Based on the information provided, the theories of "Struggle for Existence" and "Survival of the Fittest" were primarily articulated by Charles Darwin. Therefore, the correct answer to the question is Darwin.

**Final Answer**: The theories of "Struggle for Existence" and "Survival of the Fittest" were given by Charles Darwin.

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