The composition of claim 1 wherein the organopolysiloxane of component (A) is of the following formula (1): wherein R1 is a hydrogen atom or a methyl group, R2 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R2 contains at least 15 mol % of aromatic hydrocarbon groups, m is an integer of 1 to 5, and n is an integer of 80 to 1,200.