The scatter plot shows the results of a survey conducted by a T-shirt manufacturing company. A line of best fit was found for the data with the equation y -5x + 80, where y is the number of T-shirts sold and x is the price of a T-shirt.

Which of the following statements is true? a. the irrational number system is not closed under multiplication, because the product of two irrational numbers is always a rational number. b. the irrational number system is not closed under multiplication, because the product of two irrational numbers is not always an irrational number. c. the irrational number system is closed under multiplication, because the product of two irrational numbers is always an irrational number. d. the irrational number system is closed under multiplication, because the product of two irrational numbers is always a rational numbers. reset submit