Q6. Three charges \( +9 \, \mu\text{C} \), \( -6 \, \mu\text{C} \), and \( +4 \, \mu\text{C} \) are at \( (0, 0, 0) \), \( (9, 0, 0) \), and \( (0, 9, 0) \, \text{m} \). What is the potential at \( (9, 9, 0) \, \text{m} \)? (Take \( \frac{1}{4 \pi \varepsilon_0} = 9 \times 10^9 \, \text{Nm}^2 \text{C}^{-2} \)).
- A. 4200 V
- B. 4356 V
- C. 4400 V
- D. 4500 V