$\begin{array}{1 1}(a)\;\text{usually produce high spin complexes and small crystal field splittings}\\(b)\;\text{usually produce low spin complexes and small crystal field splittings}\\(c)\;\text{usually produce low spin complexes and high crystal field splittings}\\(d)\;\text{usually produce high spin complexes and high crystal field splittings}\end{array}$
