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

Options

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

Answer

**Step-by-Step Solution:**

1. **Identify the Theories**: The question asks about the theories of "struggle for existence" and "survival of the fittest." These concepts are primarily associated with Charles Darwin.

2. **Understand the Context**: The "struggle for existence" refers to the competition among organisms for limited resources, which is a key concept in natural selection. "Survival of the fittest" is a phrase often used to describe the process of natural selection, where the individuals best adapted to their environment are more likely to survive and reproduce.

3. **Recognize the Contributor**: Both theories were popularized by Charles Darwin in his work on evolution. Although the phrase "survival of the fittest" was coined by Herbert Spencer, it is closely linked to Darwin's theory of natural selection.

4. **Conclude the Answer**: Therefore, the theories of "struggle for existence" and "survival of the fittest" are attributed to Charles Darwin.

**Final Answer**: Charles Darwin.

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