I feel everyone's pain with this one. The reason I got this one wrong is also very frustrating. My thought process went something like, "the scientists is not considering that it might have been some other material in the bubbles that is responsible for the growth of the algae". I get to the answer choices, and bam! There it is. Still, I was wrong.

This question was crazy hard. I got it right though; here's why I think I did: on this particular question I was locked in. I understood what I read fairly quickly. So, when I went to the answer choices, I was able to parse out the trickery in answer choice B. I'm hoping it wasn't just luck on this one. The key, which I'm starting to take very seriously as something of an "aha" moment through my studies, is to really freakin know how to read and understand. This might not be news to anyone. I think it's well worth reenforcing this though.

I got this and the previous question wrong. However, the silver-lining is that I know why I got them wrong. I was moving too fast and didn't truly understand what I had just read. So, I crossed my fingers on this one. Going through this question slowly makes the correct answer choice stand out like a sore thumb. For the good of the group: in studying, let's emphasize fully understanding what we read.

Philosophy majors are like: true belief does not equal knowledge!