Step 1: Understand the question.
We must give the full form of CBSE. This is a well-known school board in India.
Step 2: Expand each letter.
C stands for Central, B for Board, S for Secondary, and E for Education. Putting these together gives Central Board of Secondary Education.
Step 3: Check the options against this.
One option says Selective Education, but the S means Secondary, not Selective. Two options use School Education or Body, which change the real words. So these are wrong.
Step 4: Confirm the official name.
The official and accepted full form is Central Board of Secondary Education.
Step 5: Recall its work.
CBSE conducts the Class 10 and Class 12 exams and sets the curriculum for its affiliated schools. This matches the word Secondary in its name.
Step 6: Match with the options.
The first option is correct.
\[ \boxed{\text{Central Board of Secondary Education}} \]