What is the sign of the product (-5)(-3)(-8)(-6)?

a Positive, because the products (-5)(-3) and (-8)(-6) are negative, and the product of two negative numbers is positive
b Positive, because the products (-5)(-3) and (-8)(-6) are positive, and the product of two positive numbers is positive
c Negative, because the products (-5)(-3) and (-8)(-6) are negative, and the product of two negative numbers is negative
d Negative, because the products (-5)(-3) and (-8)(-6) are positive, and the product of two positive numbers is negative