AIIMS 2017 Chemistry Hydrogen Spectrum MCQ Question

In the Balmer series for hydrogen, the wavelength of emitted light corresponds to transitions where the electron falls to the n₁ = 2 level from higher energy levels. For the wavelength to match that of the He⁺ ion transition from n = 4 to n = 2, the transition must be from n₁ = 3 to n₂ = 4 in hydrogen, as this yields a wavelength that aligns with the calculated wavelength for He⁺. Options (A) and (B) involve transitions to n₁ = 2, which would produce shorter wavelengths, while option (D) involves a transition from n₁ = 4 to n₂ = 5, which would not match the required energy difference for the same wavelength.