The answer is D. While it's important to do that, this answer doesn't have anything to do with summarizing information from sources.
Solar flares *were* the <span>cause of the difficulty, and new instruments *are* the solution.</span>
Answer:
<em>thinking that A causes B because A always comes before B</em>
Explanation:
The pen(A) has been a constant thing (always there) before every positive speech (B), so the logical line that the writer follows, is that the pen has to be there in order for a correct speech to be given, even though no direct relation is implied or stated between the blue pen and a good speech.