After an oil spill, rehabilitation centers were set up to save sea otters by removing oil from them. The effort was ...

shunhe on May 12, 2020

Hi @Maria-Marin,

Thanks for the question! Let me see if I can break down this stimulus for you. So first, we’re told that there was an oil spill, and so as a result, rehabilitation centers were set up to save otters by removing oil for them. In other words, oil needed to be taken off otters in the sea, which was done in rehabilitation centers. But then we’re told this effort wasn’t worthwhile, since there were overall 357 affected live otters and 900 dead, but only 222 were successfully rehabilitated out of that total. Then, we’re further told that the percentage of all affected that were successfully rehabilitated was even lower than 18% (222/900+357) because only a fifth of the otters that died immediately were ever found. In other words, there were 5 times more otters that weren’t even found.

Now we need something to weaken this, and the answer here is (B), because that might help question how the author knows how many otters weren’t found, since we don’t know how the author knows that.

Hope this helps! Feel free to ask any other questions that you might have.