The correct statement (s) among I to III with respect to potassium ions that are abundant within the cell fluid is /are
I. They activate many enzymes
II. They participate in the oxidation of glucose to produce ATP
III. Along with sodium ions they are responsible for the transmission of nerve signals

The major product of the following reaction is –

The correct order of atomic radii is :

The magnetic moment of an octahedral homoleptic Mn(II) complex is 5.9 BM. The suitable ligand for this complex is -