Find the missing letter in the sequence M, N, O, ?, Q, R.

A. P

If A=1, B=2, C=3, and so on, what is the code for the word 'CAT'?

A. 312

Using the same coding system, what is the numerical code for the word 'DOG'?

D. 417

If the code for 'FISH' is 6-9-19-8, what would be the code for 'BIRD'?

A. 21818

What is the code for 'WATER' if A=1, B=2, ..., Z=26?

A. 23182018