The correct answer is option 1, Pacific Ocean. The lithosphere is the rigid outer layer of the Earth, consisting of the crust and the upper part of the mantle. It is divided into several tectonic plates that float on the semi-fluid portion of the mantle called the asthenosphere. The Pacific Ocean is located along the boundaries of several tectonic plates, including the Pacific Plate, Nazca Plate, and the Philippine Sea Plate.

These plate boundaries are characterized by intense tectonic activity, including subduction zones where one plate is forced beneath another. This subduction process is responsible for the creation of deep trenches in the Pacific Ocean, such as the Mariana Trench, which is the deepest part of the Earth`s oceans.

Due to the subduction processes and the formation of trenches, the lithosphere in the Pacific Ocean experiences greater depths compared to other regions. Therefore, the maximum depth of the lithosphere is found in the Pacific Ocean.

Alert - The correct answer should be option 2, Siberian Plain. The previous answer is incorrect. The Siberian Plain is known to have the thickest lithosphere due to its stable and relatively old geological history. The area has experienced minimal tectonic activity, resulting in the preservation and accumulation of thick