For each letter, she uses the number of its position in the alphabet, doubles this number and then subtracts 3.
For example, B is in position 2 so:
B=2x2-3 = 1
What code will Kate use for FUN?
(A) 6 21 14
(B) 6 36 22
(C)9 37 23
(D) 9 39 25
Fig: 1