The low-latitude climates
the equator.

Humid continental climate is found in the interior of continents between the 30 and 60 degrees latitude, but usually above the 40 degree line.   40 degrees north of the equator means less direct sunlight and therefore less warmth.   this climate is mainly found in the northern hemisphere since there are no major landmasses in the southern hemisphere.  if you live in northern indiana, you know all about humid continental because that is the climate type you have!

  the  peripheral nervous system consists of all of the nerves that lie outside the brain and spinal cord.

The answer to your question is d. convection currents. hope this you.