The correct choice is (c) 3-D cell model
The explanation: Spheroids are a type of three-dimensional cell modeling that better simulate a live cell’s environmental conditions compared to a two-dimensional cell model, specifically with the reactions between cells and the reactions between cells and the matrix. Spheroids are useful in the study of changing physiological characteristics of cells, the difference in the structure of healthy cells and tumor cells, and the changes cells undergo when forming a tumor.