Concept:The gradient of a straight line measures how steep the line is between two given points.Explanation:Let P(5,−7) be (x1,y1) and Q(−2,−3) be (x2,y2).The formula for the gradient is:Gradient=x2−x1y2−y1Substitute the coordinates:Gradient=−2−5−3−(−7)Simplify the numerator:−3−(−7)=−3+7=4Simplify the denominator:−2−5=−7Therefore:Gradient=−74=−74Answer:C. −74