The technique that would be WRONG to use in order to avoid plagiarism is B) Use or copy another person's words or ideas from a text without crediting the original source. Plagiarism involves presenting someone else's work or ideas as your own without giving them proper credit.
The two techniques shown in the student's draft excerpt to avoid plagiarism are:
A) Use short quotations (only several keywords) as part of your own sentence.
D) Quote or copy out a group of words from a text, with an indication that you are not the original author or speaker.
In the draft, the student uses quotation marks around the words of the original author ("verbal communication has decreased dramatically") and includes the author's name (Bella Dahl) to give proper credit to the original source.