Question

select the sentence from the article that best supports its central idea.
a after all, sea turtles travel across thousands of miles of open ocean each year.
b a study published on thursday looks at loggerhead sea turtles that bury their eggs on the florida coast.
c as the geomagnetic field shifted, the turtles went to different nesting sites. it proved that sea turtles can sense magnetic signatures.
d returning turtles are not just using geomagnetism to point themselves in the right general direction, however.

Explanation:

To find the sentence that best supports the central idea, we analyze each option. Option A describes sea turtles' travel distance, which is a fact but not likely the central idea's core support. Option B introduces a study on loggerhead sea turtles but doesn't directly support a central idea about their abilities. Option C shows that sea turtles can sense magnetic signatures (as their nesting sites changed with geomagnetic shifts), which is a key finding that likely supports the central idea about their magnetic sensing ability. Option D is a contrast about geomagnetism usage but not the main supporting evidence. So, Option C provides the strongest support.

Answer:

C. As the geomagnetic field shifted, the turtles went to different nesting sites. It proved that sea turtles can sense magnetic signatures.