Character Array

Hi All,
Recently I have faced one question related to character array and the question was:
You have given a character array of size 10 and you have to copy all the elements of this character array into the another new character array which is having a size of half of the above character array. ie., 5.
char c1[10] = {‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’, ‘7’, ‘8’, ‘9’, ‘\0’};
char c2[5];

Is there anyone who can suggest me the best optimal way to do this ?