The correct option is A Dextrotatory, which rotates plane polarised light towards right
Compounds that rotate plane polarised light is called optically active compounds. Based on the direction of rotation of plane polarised light, they are classified into two types.
Compounds that rotate the plane of polarised light in clockwise direction or to the right of direction of propagation. It is indicated by (+) or d- before the compound name. These compounds are called dextrorotatory
Thus, option (a) is correct.