Which of the following do we know to be true about Desert Side-notched points and Cottonwood ...

Which of the following do we know to be true about Desert Side-notched points and Cottonwood Triangular points?
 
  a. They both post-date AD 1300.
  b. Desert Side-notched points were designed for hunting bighorn sheep, while Cottonwood Triangular points were designed for hunting rabbits.
  c. Cottonwood Triangular points were unfinished, intended to be later notched, while Desert Side-notched points were already finished.
  d. Each represents a different cultural group living side by side at Gatecliff.
  e. They are both earlier than Elko Corner-notched points.