Answer:
Answer: D; Irregular shape
Explanation: I'm not entirely positive but I do believe that the factor they're wanting you to notice in this question is the shape, as it states "deposition of the jagged particle". The shape affects the rate, as in the notes directly from the video it states "round particles settle more quickly".
Vestigial structures are inherited from ancestors, but have lost much or all of their original function due to different selection pressures acting on the descendant. The hipbones of bottlenose dolphins are vestigial structures. However, as the dolphin lineage adapted to life at sea, this function was lost.
