The number of permutations of n dissimilar things taken 'r' at a time, in which a particular thing always occurs is:
A) (n - 1)P(r - 1)
B) (n - 1)P(r - 1)
C) (n - 1)Pᵣ
D) (r!)
E) (n - 1)P(r - 1)