If productCost and productPrice are numeric variables, and productName is a string variable, which of the following statements are valid assignments? If a statement is not valid, explain why not. a. productCost = 100 b. productPrice = productCost c. productPrice = productName d. productPrice = "24.95" e. 15.67 = productCost f. productCost = $1,345.52 g. productCost = productPrice – 10 h. productName = "mouse pad" i. productCost + 20 = productPrice j. productName = 3-inch nails k. productName = 43 l. productName = "44" m. "99" = productName n. productName = brush o. battery = productName p. productPrice = productPrice q. productName = productCost