I'd say C, "The acrylic pods are created in many sizes, including big, small, and medium, as well as other sizes needed by the scientists; they are connected to the seafloor by chains and float some distance below the surface, so the plants are not destroyed by storms."
<em>The aspects of a story that best help the reader understand the author, I think, are imagery, repetition, and tone. These three help make the thoughts of the author concrete and understandable. Even more so than imagery and repetition, tone is often known and noted to be very important in understanding the author's purposes. </em>
<em>Plot and setting have more to do with characters than with the author's intentions, although they still do.</em>
<em>-Toremi</em>