Which of the following best paraphrases the underlined sentence in paragraph 2?

What explains the difference in student performance is the mental work that each method of notetaking demands, rather than the technology.

The modern device, along with the mental requirements of each method for the brain, is responsible for the difference in student performance.

The difference in student performance is attributable to the modern technology instead of the mental work that each method of notetaking requires.

Regardless of the method of notetaking, the effects on the brain exhibit little difference as long as technology is involved in student performance.