The statement that best describes the insistence is
Option C.
Step-by-step explanation:
The sentence clearly states that early adolescence and the separation from childhood has caused young people to want to act more grown up, and sexual maturity from puberty has motivated them to act in more young manly and young womanly ways.
This is the giveaway that there is an enormous pressure on the teens to act grown up and to look up to the overt serialization of the adults leading them to 'find' love and crushes.
This makes the teens pressure themselves into romance when they are not ready.