It's B, which of his or her friends should write a letter
Your answer → <u><em>substances, concepts etc that we cannot divide into separate elements.</em></u>
<u><em></em></u>
<u>does that help</u>
Answer:
I honestly can't say for 100% due to how small and pixelated the pictures are, but I'm willing to bet the first word is "Studying" and the second is "paper," "words," "books," or something else of similar nature.
Explanation:
If you could provide a higher definition screenshot/photo of the four pictures the question is referring to I'd be glad to help you further.