The correct answer is D. walk : run.
Rain and drizzle are both forms of precipitation, but drizzle is a much lighter form of rain. Similarly, walk and run are both forms of locomotion, but walking is a much slower form of running.
Swim and dive are both forms of aquatic activity, but diving is a much more specialized form of swimming. Juggle and bounce are both forms of physical activity, but juggling is a much more complex form of bouncing.
The answer is not E. run : jog. Run and jog are both forms of locomotion, but they are not on a continuum of speed. Running is a faster form of locomotion than jogging, but it is not a more specialized form of jogging.