I think there should be an age limit for social media use because if there wasn't a lot of kids would be getting in trouble for doing stuff of the social media that they shouldn't be doing.
You didn't provide the excerpt but if it's the one I found online, I think A would make the most sense as the passage is primairly based around his own actions. If not A, then D would be second choice I think.
Conjunctive adverbs connect one clause to another clause, or one idea to another idea: Joanne was very good at math; however, she is not good at English.
Descriptive adjectives can be separated with commas in a sentence such as: Joanne did not want to pet the smelly, wet dog.
One possible theme could be “how a person is affected by growing older”. Shakespeare compares old age to the seasonal shift. The narrator also describes how aging is harsh and ultimately comes to see its inevitability. Hope this helps!