When Performing a Mineral Nutrition Experiment, Researchers Use Water from a Glass

When performing a mineral nutrition experiment, researchers use water from a glass still. Why is it not a good idea to use regular distilled water from a stainless steel still?

A) With a steel still, lime deposits from hard water will build up too quickly.
B) Salts in the water corrode steel more quickly than glass.
C) Metal ions dissolving off the steel may serve as micronutrients.
D) A glass still allows the distillation process to be observed.
E) There is no difference; both kinds of stills produce distilled water.