QUESTION 4 a) Write a C++ program that asks a user to enter the product cost and its markup percentage. Then, the program should display the product retail price. For example, if the product cost is RM1000 and the markup percentage that entered by user is 50%, then the product retail price would be RM1500. Create a function name salePrice ) that receives the product cost and the markup Percentage as parameter and return the product retail price. (6 marks)