What Wavelength (In $\mu$ M)is Associated with the Paschen Series for N = 4

Multiple Choice

What wavelength (in $\mu$ m) is associated with the Paschen series for n = 4? (R_H = 1.097*10⁷ m ^{- 1})

A) 320
B) 530
C) 2.7
D) 1.9
E) 0.5