The letter C leads to a lot of pronunciation mistakes.  This is because C can be pronounced two different ways.

C can be pronounced as:

S in CITY

K in CAT

How can you tell which pronunciation to use?  Just follow these rules:

If the letter C comes before I, E, or Y, then pronounce the letter C as an S sound.

If the letter C comes before A, O, or U, then pronounce the letter C as a K sound.