What is the difference between random sampling and random assignment

Ithink the answer is d

Answerradius is the lateral bone of the forearm when considering the anatomical position, it is wide at its distal, and narrow at its proximal;

ulna forms the elbow joint with humerus at its proximal end with its olecranon process. the ulna is slightly larger than the radius;

ok i looked up raial, and theres no such bone in the human body /// check the spelling/// both of the above bones are in your lower forearm you'll get it good luck/