Which one of the following is a membrane that protects the developing embryo from desiccation ?

The amnion is the extraembryonic membrane that encloses the embryo in a fluid-filled sac (the amniotic cavity), providing a stable, hydrated microenvironment that prevents drying out and allows development away from aquatic habitats. Text sources describe amniotic fluid surrounding the fetus and note that the amnion forms a fluid-filled cavity that supplies an internal aquatic environment, reducing dependence on external water and protecting against desiccation and mechanical shock [2]. Thus among the given choices, the amnion is the membrane whose primary role is to maintain hydration and protect the developing embryo from desiccation.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 3: Geological Time Scale The Evolution of The Earths Surface > Carboniferous Period (360 mya to 300 mya) > p. 45
2. [2] https://bio.libretexts.org/Courses/Lumen_Learning/Fundamentals_of_Biology_I_(Lumen)/15%3A_Module_12-_Vertebrates/15.05%3A_Amniotic_Animals