One of the causes of variation known by early agriculturists, was hidden in
(a) Formation of diploid gametes
(b) Fusion of identical gametes
(c) Sexual reproduction
(d) Both (a) & (b)

Options

A. Formation of deploid gametes
B. Fusion of identical gametes
C. sexual reproduction
D. Both (1) & (2)

Answer

To solve the question regarding the cause of variation known by early agriculturists, we can analyze the options provided step by step.

### Step 1: Understand the question
The question asks about the cause of variation recognized by early agriculturists. Variations are essential for the process of evolution and selective breeding, which were crucial for agricultural practices.

### Step 2: Analyze the options
- **Option (a): Formation of diploid gametes**
- Diploid gametes refer to gametes that contain two sets of chromosomes. However, in sexual reproduction, gametes are typically haploid (one set of chromosomes). Therefore, this option does not directly relate to the cause of variation recognized by early agriculturists.

- **Option (b): Fusion of identical gametes**
- The fusion of identical gametes would not lead to variation. Instead, it would produce offspring that are genetically identical to the parents, which does not contribute to variation.

- **Option (c): Sexual reproduction**
- Sexual reproduction involves the combination of genetic material from two parents, leading to offspring that have a mix of traits from both. This process is a significant source of genetic variation, which early agriculturists would have recognized as crucial for developing new plant varieties.

- **Option (d): Both (a) & (b)**
- Since both (a) and (b) do not contribute to variation, this option can be eliminated.

### Step 3: Conclusion
Based on the analysis, the most accurate answer is **(c) Sexual reproduction**. This is because sexual reproduction is the process that introduces genetic variation among offspring, which early agriculturists would have recognized and utilized in their practices.

### Final Answer
(c) Sexual reproduction