If the letters of the word REGULATIONS be arranged at random, find the probability that there will be exactly four letters between the `R` and the`Edot`

Options

A. `(11!)/("'^9C_4 6!)`
B. `(12!)/(""^9C_5 6! 2!)`
C. `(11!)/(""^9P_4 6!2!)`
D. `(11!)/(""^9C_4 6! 2!)`