The correct answer is A) and B). Hope this helps.
External skeleton is the correct answer. Hope this helps out !
The best evidence of such phenomena could be a population's genetic variation decrease.
When a population bottleneck occur it means that for some reason (i.e. environmental events) the size of a population is largely reduced. This leads to reduction of the genetic variation in that new smaller population. When a bottleneck occur, the founder effect is normally seen, which is that one population is established by a small group of a previously larger population leading once again the genetic variation, now though with a bigger population, to be very reduced.
The answer is (C), because, red blood cells or wbc regulate body temperature (Idr), wbc fight infections, and rbc transport nutrients
