Final answer:
In Maslow's Hierarchy of Needs, 'peaceful sleep' and 'adequate oxygen' fit into the category of physiological needs as they are essential for survival and must be satisfied before other higher-level needs.
Step-by-step explanation:
Matching each need from Maslow's Hierarchy with the appropriate examples, 'peaceful sleep' and 'adequate oxygen', we can deduce that these examples belong to the most basic level of Maslow's Hierarchy: physiological needs. Physiological needs are those that are necessary for survival, such as food, water, warmth, rest, and breathing. As the foundation of the hierarchy, these needs must be met before higher-level needs become relevant to an individual.
Peaceful sleep contributes to good health and well-being, addressing the physiological need for rest. Similarly, adequate oxygen is a basic requirement for respiratory function, making it another physiological need. These examples emphasize how fundamental survival needs must be satisfied to progress to higher tiers of Maslow's pyramid, which include safety, love/belonging, esteem, and self-actualization.