**Category:** Electromagnetism  
**Subtype:** Photoelectric Effect  
**Problem Description:** Find the threshold wavelength (limit) for the photoelectric effect of a metal given its work function.  

**Summary:** The problem involves calculating the threshold wavelength for the photoelectric effect of a metal with a given work function of \( A = 7.64 \times 10^{-19} \, \text{J} \). The options provided are different wavelengths in nanometers (nm).