Final answer:
Eduardo's hair strand is thicker with a diameter of 0.012 cm compared to Orla's strand which has a diameter of 0.005 cm.
Step-by-step explanation:
The question asks for the comparison of the diameter of two hairs observed under a microscope. Orla's hair strand measured 0.005 cm in diameter, and Eduardo's measured 0.012 cm. To determine which hair strand is thicker, we need to compare these two measurements. Since 0.012 cm is greater than 0.005 cm, Eduardo's hair strand has a larger diameter and is therefore thicker.
Therefore, the correct answer is b. Eduardo's strand is thicker. Orla's strand is not thicker, nor do both strands have the same diameter, and it is possible to determine the comparison from the given measurements.