Mark the correct option w.r.t hydroponics

Options

A. It can avoid problem of soil borne pathogens.
B. In 1860, Julius von Sachs, a prominent German botanist demonstrated ,it for the first time.
C. It helps in determining a mineral solution for the plant growth was obtained.
D. All of these

Answer

To solve the question regarding hydroponics, we will analyze each option provided to determine which one(s) are correct.

### Step-by-Step Solution:

1. **Understanding Hydroponics**:
- Hydroponics is a method of growing plants without soil, using nutrient-rich water solutions. This technique allows for precise control over nutrient delivery and can lead to faster plant growth and higher yields.

2. **Evaluating the Options**:
- **Option A**: "It can avoid the problem of soil-borne pathogens."
- This statement is true. Since hydroponics does not use soil, it eliminates the risk of soil-borne diseases and pathogens that can affect plant health.

- **Option B**: "In 1860, Julius von Sachs, a prominent German botanist, demonstrated it for the first time."
- This statement is also true. Julius von Sachs is known for his work in plant physiology and was one of the first to demonstrate hydroponic techniques.

- **Option C**: "It helps in determining a mineral solution for plant growth."
- This statement is true as well. Hydroponics allows for the precise formulation of nutrient solutions tailored to the specific needs of plants, which is crucial for optimal growth.

- **Option D**: "All of these."
- Since options A, B, and C are all correct, this option is also correct.

3. **Conclusion**:
- The correct answer is **Option D: All of these**, as all the statements regarding hydroponics are accurate.

### Final Answer:
**D: All of these**