A composition containing: a compound (2); a metal compound; and at least one selected from a compound (3) and a compound (4), the compound (3) being contained in an amount of 10000 ppm or less relative to the compound (2), the compound (4) being contained in an amount of 10000 ppm or less relative to the compound (2), the compound (2) being represented by the following formula (2):




the compound (3) being represented by the following formula (3):




and the compound (4) being represented by the following formula (4):




wherein the various substituents of compounds (2), (3) and (4) are as defined herein.