The correct option is B H2SO4
A strong acid produces a large amount of H+(aq) ions in the aqueous solution.
H2SO4 is a strong acid because it easily gives H+(aq) ions in water.
C2H5COOH, HCOOH and CH3COOH partially dissociate in water, i.e., release less amount of H+(aq) ions. Therefore, they are weak acids.