To answer this question, we need to understand which state was the first to implement the proposal of including the environment as a separate subject in schools.
Option A) Uttar Pradesh - This option is incorrect because Uttar Pradesh was not the first state to implement the proposal.
Option B) Tamil Nadu - This option is incorrect because Tamil Nadu was not the first state to implement the proposal.
Option C) Maharashtra - This option is correct because Maharashtra was the first state to implement the path-breaking proposal of including the environment as a separate subject in schools.
Option D) Kerala - This option is incorrect because Kerala was not the first state to implement the proposal.
The correct answer is C) Maharashtra. This option is correct because Maharashtra was the first state to implement the proposal of including the environment as a separate subject in schools.