Which quantity and unit are correctly paired?

SI units are the standard units that are recommended by the IUPAC. The units of velocity is m/s since it is given by dividing displacement (m) and time (s).
Momentum is the product of velocity (m/s) and the mass(kg) of a body, thus its units are kgm/s. Work is given by the product of force (N) and distance (m), thus its units are Ns or Joules. Energy is measured in kg m²/s². Hence the correct answer is 3

A. radioactive dating