Option 1: Maharashtra is known for its cotton production, but it is not solely dependent on irrigation. While some parts of Maharashtra practice irrigation-based cotton cultivation, other regions rely on rainfed farming methods as well. Therefore, option 1 cannot be the correct answer.

Option 2: Madhya Pradesh is a significant cotton producing state, but cotton cultivation in this state is not entirely dependent on irrigation. Similar to Maharashtra, Madhya Pradesh also practices a combination of irrigation-based and rainfed cotton farming. Hence, option 2 is not the correct answer.

Option 3: Rajasthan is not primarily known for cotton cultivation. The state`s arid climate and limited water resources make it challenging to depend solely on irrigation for cotton farming. Therefore, option 3 is not the correct answer.

Option 4: Haryana, on the other hand, is a state where cotton cultivation is predominantly based on irrigation. The state has a well-developed canal irrigation system, which facilitates water supply to cotton fields. Therefore, option 4 is the correct answer.

Thus, the answer provided in the question is correct, and Haryana is the state where cotton cultivation is mainly based on irrigation.