Match List-I with List-II and select the correct answer using the code given below the Lists : List-I List-II (Hypothesis/ Theory) (Propou nder) A. Planetesimal hypothesis 1. Kober B. Thermal contraction 2. Chamberlin theory C. Geosynclinal Orogen 3. Daly theory D. Hypothesis of sliding 4. Jeffreys continent Code :

The correct matching of theories with their propounders is as follows: The Planetesimal hypothesis was postulated by T.C. Chamberlin and Forest Ray Moulton in 1905, suggesting planets formed from small solid bodies. The Thermal Contraction theory is attributed to Harold Jeffreys, who argued that the Earth's cooling led to contraction and mountain building [1]. The Geosynclinal Orogen theory was developed by Leopold Kober, who described the formation of mountains through the compression of sediments within geosynclines. Lastly, the Hypothesis of Sliding Continents (or Continental Sliding) was proposed by Reginald Aldworth Daly, who suggested that gravity-driven sliding of the crust over a slippery substratum caused mountain formation. Therefore, the correct sequence is A-2, B-4, C-1, D-3, which corresponds to Option 1.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 2: The Solar System > Earlier Theories > p. 17