Final answer:
Simple squamous epithelium, suited for rapid substance exchange, is located in the alveoli of the lungs, while non-keratinizing stratified squamous epithelium is found in the inner lining of the mouth, esophagus, and rectum.
Step-by-step explanation:
The location of simple squamous epithelium in the human body is associated with areas where rapid exchange or passage of substances is essential. This type of epithelium can be found in the alveoli of the lungs, where it facilitates the diffusion of gases, making it an ideal match for the option 1) Lungs from the student's question.
Moreover, non-keratinizing stratified squamous epithelium is present in areas that require protection but are not exposed to the external environment and thus do not require keratin for waterproofing. These locations include the inner lining of the mouth, esophagus, and part of the rectum, where protection against abrasion is important without the need for keratinization.