Concept:A proper fraction has a numerator smaller than the denominator. Factorisation of a quadratic polynomial into two linear factors lets us identify the constants.Explanation:Factorise 10x2+x−3 by splitting the middle term. Find two numbers whose product is 10×(−3)=−30 and sum is 1. The numbers are 6 and −5.Rewrite: 10x2+6x−5x−3Group: 2x(5x+3)−1(5x+3)=(5x+3)(2x−1)Compare with (ax+b)(cx+d). Since a>c, we take a=5, b=3, c=2, d=−1.Now compute a+cb+d=5+23+(−1)=72.Since numerator 2 is less than denominator 7, the result is a proper fraction.Answer:B. a proper fraction