Given two moving objects, a 50 kg person and a 10 kg dog, which of the following statements about their scalar momenta is true, assuming the dog has the greater speed?: A. The momenta of the person and dog are constant at 50 kg and 10 kg, respectively. B. The momenta of both will vary based on speed, but the dog's maximum will be less than the person's minimum. C. The dog will have the greatest momentum, but specific values depend on the speeds of each. D. The dog may have equal, greater, or lesser momentum, depending on the actual speeds of each.