Read the following code, written to calculate an average: def main(): num1 = 85 num2 = 95 num3 = 91 average = num1 + num2 + num3 / 3 print("Average: " + str(average)) main() Which line of code has an error and why? average = num1 + num2 + num3 / 3; It does not use quotation marks to indicate the string literal. average = num1 + num2 + num3 / 3; It does not follow the proper order of operations. print("Average: "str(average)); It requires an equal sign to properly calculate the output. print("Average: "str(average)); It requires a float() function to properly display the output