Smallest wavelength occurs for: Lyman series, Balmer series, Paschen series, Brackett series

Series → Lyman, Balmer, Paschen, Brackett, Pfund
────────────────────────────────────────────────────→ Increasing wavelength
By using, 1/λ = R(1/n₁² - 1/n₂²)
For smallest wavelength n₁ and n₂ are the nearest orbital.
If we use n₁ in the ground state and n₂ at ∞, then we get Lyman series have the smallest wavelength.
Hence, option A is correct.