Diabetescan result in an immunodeficiency disorder because white blood cells do not function well when the blood sugar level is high<span>. Human immunodeficiency virus (HIV) infection results in acquired immunodeficiency syndrome (AIDS), the most common severe acquired immunodeficiency disorder.</span>
This is an effective strategy because different phases do not compete for food.
For example for the case of Jelly fish, After a brief period floating about in surface waters like planktons, the larvae then settles to the sea floor, attaching themselves to one end. They then develop to polyps and begin to feed and grow. In spring the polyps bud iff immature jellyfish known as ephyra larvae which then grow to mature jellyfish.
A because it pertains the the ecosystem
I would go with the first option