C-09-Q026mediumsingle_mcq(a2b3)5(a^2 b^3)^5(a2b3)5 equals:aa10b15a^{10}b^{15}a10b15ba7b8a^{7}b^{8}a7b8ca25b15a^{25}b^{15}a25b15da2b15a^{2}b^{15}a2b15