The lens formula is ______

• A. \(\frac{1}{u} - \frac{1}{v} = \frac{1}{f}\)
• B. \(\frac{1}{v} - \frac{1}{u} = \frac{1}{f}\)
• C. \(\frac{1}{f} - \frac{1}{u} = \frac{1}{v}\)
• D. \(\frac{1}{v} + \frac{1}{u} = \frac{1}{f}\)