Sea turtles nest only at their own birthplaces. After hatching on the beach, the turtles enter the water to begin the...

shunhe on July 22, 2020

Hi @Veda-Bhadharla,

Thanks for the question! So the passage is telling us about sea turtles, which nest at their own birthplaces. They hatch, and then go into the water and migrate, and return to their birthplaces years later. Some have hypothesized that newborn sea turtles learn the smell of their birth environment, and so that’s how they find it all those years later.

Now we’re asked for something that would help us evaluate this hypothesis. Take a look at (D), which tells us that knowing the answer to if the turtles are outside the area where the smell of their birthplace would be perceptible would help. Well, let’s say that they are outside the area. Then that means that the hypothesis can’t be true, since there’s no way they could smell their birthplace, but they still find their way back, so it has to be another method that they find their birthplaces. But if they are in the area where they can still smell their birthplace? Then the hypothesis is still viable. So knowing the answer to (D) would help us evaluate the hypothesis, and so (D) is the right answer.

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