Which sentence from the passage includes an example of reasoning that is not valid?

Answer choices for the above question

“Shorthand, or a codified language designed to make writing faster, has been around for generations.” (paragraph 1)

“The shorthand of today’s world is one of abbreviated words and phrases linked to texting.” (paragraph 2)

“There are three particular areas in which this shorthand rears its head: abbreviations, lack of basic grammar, and reliance upon the artificial intelligence of the machine.” (paragraph 3)

“While students may explain that they text more often than they write and, therefore, that text shorthand is just a habit, they need to break such a habit to be successful adults.” (paragraph 5)