Option 1 suggests that just statements 1 and 2 are correct. Statement 1 is accurate - Brihadratha, the final Mauryan ruler, was indeed killed by Pushyamitra Sunga. Statement 2 is also correct - Devabhuti, the last Sunga king, was assassinated by Vasudeva Kanva, who then took his place.

Option 2 suggests that only statement 2 is correct. As mentioned earlier, this statement is accurate as Devabhuti was assassinated by Vasudeva Kanva.

Option 3 states that only statement 3 is correct. This is accurate - the Andhras did depose the final ruler of the Kanva dynasty.

Option 4 confirms that all three statements, 1, 2, and 3 are correct. Given the historical facts stated earlier - Brihadratha was assassinated by Pushyamitra Sunga, Devabhuti was assassinated by Vasudeva Kanva, and Andhras did depose the last Kanva ruler, this fourth option is the correct one. Each of the three statements is true. Thus, the given answer is correct.