The correct answer is (a) Morahana Pahar.
Morahana Pahar is a rock shelter located in the Vindhya Range in the Indian state of Uttar Pradesh. It is a significant archaeological site, as it has yielded a large number of human skeletons, as well as other artifacts. The skeletons are believed to be from the Mesolithic period, and they provide valuable insights into the lives of early humans in India.
The other options are incorrect. Ghagharia is a rock shelter located in the Vindhya Range in the Indian state of Madhya Pradesh. It is also an important archaeological site, but it has not yielded as many human skeletons as Morahana Pahar. Baghahi Khor is a rock shelter located in the Vindhya Range in the Indian state of Uttar Pradesh. It is not as well-known as Morahana Pahar or Ghagharia, and it has not yielded any human skeletons. Lekhahia is a rock shelter located in the Vindhya Range in the Indian state of Madhya Pradesh. It is not an archaeological site, and it has not yielded any human skeletons.