The mass of one Avogardos number of molecules is termed as:

A. Molar mass

B. Mole

C. Atomic mass

D. Molecular mass

Avogadro's number is defined as the number of elementary particles (molecules, atoms, compounds, etc.) per mole of a substance. It is equal to 6.022×1023 mol-1 and is expressed as the symbol NA.
hence option A is correct.