Longest wavelength of the Paschen series of hydrogen

1. A.
   $1.094 \times 10^{- 6}\text{ }m$
2. B.
   $2.973 \times 10^{- 6}\text{ }m$
3. C.
   $3.646 \times 10^{- 6}\text{ }m$
4. D.
   $1.876 \times 10^{- 6}\text{ }m$

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