The plot below shows the kinetic energy of ejected electrons as a function of the frequency of radiation done to study the photoelectric effect. Calculate the frequency at point A in s^-1 if it corresponds to light with a wavelength of 756 nm. 

• A. 3.97x10¹⁴ s^-1
• B. 5.61x10¹⁴ s^-1
• C. 1.23x10¹⁴ s^-1
• D. 7.84x10¹⁴ s^-1

Answer: (A)