White Blood Cells could be a possible answer. Not sure if this is multiple choice or not.
Weathering is a natural process by which the surface mineral of rocks is carried away by various agents .The agents can be water,wind,and ice. weathering means disintegration of rocks and the small parts are being carried away by these agents and are found on different places.Weathering of rocks depends on the many factors such as climatic conditions,type of rock,water availability and many more.The small rocks mix with soil and helps form sediment .This sedimentation helps to shape the earth's surface.This is an important part of rock cycle and is very important.
The most common technique would be x-ray as it clearly displays bones.
The most complex cellular organization is actually the organisms but since its not on the choices its the organs.
