Another substance of the category of glucose, sucrose and maltose is-

Which monosaccharide does not show optical isomerism:

Correct order of abundance of oxygen, sulphur, magnesium and calcium in the earth crust?

Which one of the following structural formulae of two organic compounds is correctly identified along with
its related function?  

Which one out of $\mathrm{A}-\mathrm{D}$ given below correctly represents the structural formula of the basic amino acid?

$\mathbf{A}$	$\mathbf{B}$	$\mathbf{C}$	$\mathbf{D}$