The display in D1 should read Colin McCain what text function should be used

The answer is "SUBSTITUTE(D1,"c","C",1)"

Explanation:

In the given question, some information is missing, that is an option so, the correct option can be described as follows:  

Many of us use the Bulletin feature, which is available in MS-Excel.  In these function the SUBSTITUTE is a method, that is used in Builtin to aim the functions to locate a string or character and to replace with the selected module.  In the case of the end-user, it would like to replace "c" with a capital letter "C." And displays cell shifts in D1. This method uses 4 parameters, in which first describes cell reference, second string to located, third replacing string, and fourth its length.