What is the sign of the product (−7) × ( −2) × ( −5) × (1)? a) positive, because the products (−7) × (−2) and (−5) × (1) are negative and the product of two negative numbers is positive. b) positive, because the products (−7) × (−2) and (−5) × (1) are positive and the product of two positive numbers is positive. c) negative, because the product (−7) × (−2) is positive and the product (−5) × (1) is negative and the product of a positive and a negative number is negative. d) negative, because the product (−7) × (−2) is negative and the product (−5) × (1) is negative and the product of two negative numbers is negative.