How would you declare a variable called fullName that contains both John's first and last name?

The chosen answer accurately demonstrates how to concatenate two strings to create a single variable that holds a full name. In this case, firstName and lastName represent variables that would contain John's first name ("John") and last name ("Smith"). By using the + operator, you can combine these two variables into one string, with a space in between to format it correctly. The addition of the string " " ensures that the first name and last name are separated properly when combined, resulting in "John Smith".

This approach effectively uses string concatenation to build the desired output, which is especially useful when dealing with dynamic data where the names might not be hardcoded. Placing the space in quotes ensures that it is interpreted as a string itself and included in the final output. Thus, the result stored in fullName will be the correctly formatted representation of John’s complete name.