The Subsidiary Alliance was a policy introduced by Wellesley, who was the Governor-General of British India. Therefore, option 1 is correct.

Under the Subsidiary Alliance, the British army was indeed stationed in the subsidiary state to maintain control and protect British interests. So, option 2 is also correct.

Option 3 states that the Subsidiary Alliance did not recognize an adopted heir to a subsidiary state. This is the incorrect statement. The Subsidiary Alliance did recognize an adopted heir as long as the British approved of the adoption. This allowed the British to have a say in the succession of the subsidiary states and maintain their control. So, option 3 is the correct answer.

Option 4 states that a British Resident was posted in the subsidiary state. This is correct. The British Resident acted as a representative of the British government and monitored the affairs of the subsidiary state, ensuring that the state followed the terms of the Subsidiary Alliance.

In conclusion, option 3 is not correct about the Subsidiary Alliance, as it did recognize an adopted heir to a subsidiary state.