How many ways are there to distribute 8 different books among 21 children if no child gets more than one book? a. Combination; Subscript 13 Baseline C Subscript 8 Baseline = 1287 b. Combination; Subscript 21 Baseline C Subscript 8 Baseline = 203,490 c. Permutation; Subscript 21 Baseline P Subscript 8 Baseline = 8,204,716,800 d. Permutation; Subscript 13 Baseline P Subscript 8 Baseline = 51,891,840 pleasee help asap