The passage provides information in support of which one of the following assertions? A. The seemingly erratic motion exhibited by a microorganism can in fact reflect a mechanism by which it is able to control its movement. B. Biologists often overstate the complexity of simple organisms such as bacteria. C. A bacterium cannot normally retain a memory of a measurement of the concentration of an attractant. D. Bacteria now appear to have less control over their movement than biologists had previously hypothesized. E. Photosynthetic bacteria appear to have more control over their movement than do bacteria that are not photosynthetic.