Gargi, Maitreyi, and Kapila were ancient Indian philosophers and scholars. The home of Gargi and Maitreyi was in Mithila, an ancient kingdom that corresponds to the present-day region of northern Bihar and parts of Nepal. Kapila was associated with the Sankhya school of philosophy and is often considered one of the founders of this philosophical tradition.

1. Simlipal Bio-Reserve (Sanctuary) is located in Orissa.

2. The biosphere reserve has the largest area of sal in the whole of India. Furthermore, the tropical monsoon climate provides ideal conditions for the development of a distinctive biodiversity, highlighted by 1,076 species of vascular plants.

3. These include 93 species of orchids, 300 species of medicinal plants and 52 species of endangered flora. The two endemic species of orchid are Eria meghasaniensis and Taenia hookeriana.

4. Notable botanical species in the sanctuary include Callicarpa arborea (a species of beautyberry), Bombax ceiba (cotton tree) and Madhuca longifolia (manhua).

The invention of the railway engine is credited to George Stephenson. The correct answer is (D) George Stephenson. George Stephenson, an English engineer, is known for developing the first practical steam locomotive, named "The Rocket," which played a crucial role in the early development of railways.