I think it would be ‘problem and solution’ but i haven’t read the article because it isn’t linked. however ‘problem and solution’ does sound like it would fit best :)
Answer: He was going to buy three things: chairs, tables, and utensils.
Explanation:
The most basic rule for using commas is that they are used to separate independent clauses joined by coordinating conjunctions (and, but, for, or, nor, so, yet).
However, it might be difficult to remember that this rule still applies when we want to separate three or more words, phrases, or clauses written in a series. We must not forget to place a comma before "and".
I think the incorrect pronoun shift would be the line "<span>before you adopt a pet". I think it should be before one adopts a pet. This is because the sentence started with "It is". The "you" made the sentence very confusing. The second pronoun should be singular, the pronoun you is often denoted as plural and not singular.</span>