The correct answer is option 4, Lakshmi Sehgal. The Rani Jhansi Regiment was the Women`s Regiment of the Azad Hind Fauj, which was the armed forces of the Indian National Army (INA) established during World War II. Lakshmi Sehgal was a prominent figure in the Indian independence movement and played a crucial role in the INA.

Option 1, Usha Mehta, is not the correct answer. Usha Mehta was a freedom fighter and a prominent leader in the Quit India Movement, but she was not associated with the Rani Jhansi Regiment.

Option 2, Anne Mascarene, is not the correct answer. Anne Mascarene was a British-born Indian freedom fighter, but she had no direct connection to the Rani Jhansi Regiment.

Option 3, Aruna Asaf Ali, is not the correct answer. Aruna Asaf Ali was also a prominent figure in the Indian independence movement, but she was not associated with the Rani Jhansi Regiment either.

Therefore, the Rani Jhansi Regiment, the Women`s Regiment of the Azad Hind Fauj, was under the command of Lakshmi Sehgal.