Which statement is TRUE concerning a towing vessel which，due to the nature of her work，is unable to keep out of the way of another vessel?（）

A. By day，she shall carry a black cylinder shape
By day，she shall carry two black balls in a vertical line
C. By night，she would show the same lights as a vessel not under command
D. By day，she would show the same shapes as a vessel restricted in her ability to maneuver