Step 1: Read the goal.
The question asks for the main objective of school education. We want the broadest and truest aim.
Step 2: Think about why we teach.
Schools do far more than push students through tests. They try to shape good, capable, and caring people for society.
Step 3: Meaning of holistic development.
Holistic development means growing the child in many ways at once, the mind, the body, the feelings, and social skills together.
Step 4: Look at the narrow options.
Preparing only for exams, focusing only on academics, or just memorising textbooks each cover one small part. They miss the full growth of a child.
Step 5: Compare with modern aims.
Modern education stresses values, creativity, and life skills, not rote learning alone. Only the holistic choice captures all of this.
Step 6: Conclude.
So the main objective is the holistic development of learners, which is option 1.
\[ \boxed{\text{Holistic development of learners}} \]