Which of the following could be optically active?

Optically activity is the property of certain dissymmetric compounds containingone or more asymmetric or chiral carbon atoms to rotate the plane of polarized lightclock wise (or) anticlock wise.The compound is called optically active compound.option (1) CH3−C|ClH−CH3  is symmetricoption (2) CH3−CH2−C|BrH−CH2−CH3  is symmetricoption (3) CH3−C|CH3−CH2−CH3  is symmetricoption (4) CH3−C|Br*H−CH2−CH3  is asymmetric and optically active