The correct option is D Common entrance exam for rural and urban students
Equitable development refers to different people requiring different opportunities to reach the same outcome.
In situations 1,2, and 3, people are given opportunities according to various economical, social, and regional differences. These are equitable development.
In case 4, providing a common entrance exam for rural and urban students, may look like a just way to choose. However, we should keep in mind the lifestyle of students in the rural areas and urban areas. Rural areas may demand students to go out to the field help their parents, which is not the case with urban students.