Which biology course should I take?

This is for college BTW. I already took general zoology and made an A in it. :) I need to know if I should take Vertebrate Zoology or Invertebrate Zoology? I am already going to be taking: general chemistry, art appreciation, anatomy and physiology w/Lab. Which cl is easier? Vertebrate or Invertebrate zoology? Also, which cl is more interesting?