The correct answer is option 4, `Neither 1 nor 2`. This is because both statements are incorrect.

Statement 1 is incorrect: INS Sindhughosh is not an aircraft carrier, but rather a diesel-electric submarine of the Indian Navy`s Sindhughosh class.

Statement 2 is also incorrect: INS Viraat is not a submarine, instead, it is an aircraft carrier. It was the flagship of the Indian Navy before it was decommissioned in 2017. Thus, neither of the statements are correct rendering the option of `Neither 1 nor 2` as the correct one.

In short, both the options 1 `1 only` and 2 `2 only` are incorrect, as neither of the statements 1 and 2 are correct. Option 3 `Both 1 and 2` is also incorrect as both statements are incorrect. So, by elimination and fact-checking, the correct answer is clear - option 4 `Neither 1 nor 2`.