Read the following expression chosen from academic introductions, and identify what part of an introduction it refers to：The remainder of the paper is organized as follows: Section II gives a general description of NOMA with SIC. Then Section III details the proposed iterative method for spectrum optimization. Simulation results are given in Section IV, and Section V concludes the paper.

A.Problems with existing studies

B.Description of the skeleton of the research

C.Existing studies on the problem

D.Research contents

正确答案：Description of the skeleton of the research