I'm here to help! In this question, you are asked to find the cardinal number for the set C, which is defined as the set of all letters in the English alphabet.
To determine the cardinal number of the set C, we need to count the number of elements in the set, which in this case are the letters of the English alphabet.
1. The English alphabet consists of 26 letters from A to Z.
2. Therefore, the cardinal number of the set C, which represents the English alphabet, is 26.
So, the cardinal number for the set C = {x | x is a letter in the English alphabet} is 26. This indicates that there are 26 letters in the English alphabet.