These are two concentric circles of radius 3 and 4 at the origin. That means that any point within the inner is also within the outer. So focusing on the inner, the points plugged into its equation must be less than or equal to the radius squared or 9. That is only valid with point D.
Since the total weight would be equal to the weight of the firefighter added to the weight of the equipment, the total weight would be x+60. So the answer is B. t=x+60
