The correct answer is option 4, which includes all three options mentioned. Article 21 of the Constitution of India guarantees the right to life and personal liberty to every citizen. This article has been interpreted by the Supreme Court to include various aspects of human rights.

Option 1 is correct because the Supreme Court has recognized the rights of transgenders as part of their right to equality and non-discrimination. They have the right to self-identify their gender and must be protected from discrimination and violence.

Option 2 is correct because the Supreme Court has also recognized the rights of craniopagus twins, who are conjoined at the head. They have the right to life, personal liberty, and dignity, and any medical intervention in their case must be in their best interest.

Option 3 is correct because mentally retarded women also have the right to personal autonomy and decision-making. They have the right to marry, bear children, and make informed choices regarding their reproductive health.

Therefore, all three options are included in Article 21 of the Constitution of India.