Answer:
"s.lower()" is the correct answer to the given question.
Explanation:
Because the string value "McGraw15" stored in the string data type variable i.e "s" and after the output, the following string converted from Uppercase into the Lowercase "mcgraw15" with the help of lower() method.
lower() function is the built-in string function that converts all the uppercase string values into the lowercase string value and if the value is already in lowercase than it will remain same.