Which of the following ions is most paramagnetic

[Xe] 4f⁴ 6s², it has 4 unpaired electrons if 6s electrons are removed. The paramagnetic substances are those which are attracted by magnetic field and have unpaired electrons. The greater the number of unpaired electrons greater is the magnetic moment. Example are Tungsten, Caesium, Aluminium, are a few examples of paramagnetic substances. To calculate magnetic moment we use the equation μ=√n (n+2), where n is the number of unpaired electrons. Greater the n value, greater will be the magnetic moment.