Answer:
D). Building in Redundancy.
Step-by-step explanation:
The authors/speakers employ a variety of techniques or strategies to convey their intended idea or thought effectively to the readers.
In the given question, Sheena employs 'building in redundancy' that implies presenting the same information more than once to enhance the audience recall. She repetitively displays the same information as reflected by her presentation 'concluded..intro..previewing..main points, 'used internal summary', 'internal preview'), (in conclusion..summarized idea...importance of Curie's life'). Thus, her technique would be categorized as 'building in redundancy' which however leads to add superfluous elements in the content and fails to create the desired impact. Thus, option D is the correct answer.