Answer
See the answer below.
Work Step by Step
a) All these lines are in the infrared spectrum.
b) No.
c) The 837.761 nm is the most energetic because it has a lower wavelength (higher frequency).
d)
$c=\lambda\times\nu$
$\nu=2.998\times10^8\ m/s\div 837.761 \times10^{-9}\ m=3.58\times10^{14}\ 1/s$
$E=h\times\nu$
$E=6.626\times10^{-34}\ J.s\times 3.58\times10^{14}\ 1/s=2.37\times10^{-19}\ J$
