AP EAPCET 07-Jul-2022 Shift 1 Paper

In paschen series electron transmits from some higher state to n=3‌states

So photons of paschen series have energies ranging from :
Emin=En=4−En=3
=−0.85−(−1.5l)
=0.66‌eV
to Emax=En=∞−En=3
=0−(−1.5l)
=1.51‌eV
So, if a photon of paschen series able to emit a photoelectron from a metal, then work function φ0 of metal must be such that,
φ0≤ Photon energy
or φ0≤1.51‌eV
Only matching option is options (c) and (d).