VITEEE 2021 Paper

Sc3+(Z=18):1s2,2s2p6,3s2p6d0,4s0; no unpaired electron.
Cu+(Z=28):1s2,2s2p6,3s2p6d10,4s0; no unpaired electron.
Ni2+(Z=26):1s2,2s2p6,3s2p6d8,4s0unpaired electrons are present.
Ti3+(Z=19):1s2,2s2p6,3s2p6d1,4s0‌unpaired‌electron‌is‌present
Co2+(Z=25):1s2,2s2p6,3s2p6d7,4s0unpaired electrons are present
So from the given options the only correct combination is Ni2+ and Ti3+.