Which of the following organisms has the largest surface area-to-volume ratio?

Explanation

Amoeba has the largest surface area-to-volume ratio among the organisms listed in the options. This is because amoeba is a unicellular organisms with a relatively large surface area compared to their volume.

As the size of an organism increases, its volume increases faster than its surface area. This means that the surface area to volume ratio decreases as the organism gets larger.