Which of the following is a trace element ?

Which of the following is trace element ?

Which of the following is trace element ?

Which of the following is not a trace element?

Which of the following is not a trace element?

Which one of the following is a trace element for animal body?

Which one of the following is a trace element for animal body ?

Which one of the following is a trace element for animal body? (a) Phosphorus (b) Magnesium (c) Chlorine (d) Manganese

Which of the following is most suitable method for removing the traces of water from ethanol ?