Answer:
The answer to this question is B
<em>Structure and Function of ArthropodsArthropods range in length from about 1 millimeter to 4 meters (about 13 feet). They have a segmented body with a hard exoskeleton. They also have jointed appendages. The body segments are the head, thorax, and abdomen. </em><span><em> In some arthropods, the head and thorax are joined together as a cephalothorax.</em></span>
Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle's convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor.
Answer:
recombinat DNA , epidemiology,
