Which oil is known to have calming properties and belongs to the oxides group?

The correct choice highlights German Chamomile as being known for its calming properties and belonging to the oxides group. German Chamomile is rich in an active component called chamazulene, which not only provides the oil's characteristic blue color but also contributes significantly to its soothing and calming effects. This makes it particularly effective in alleviating anxiety and promoting relaxation, thereby making it a popular choice in aromatherapy for stress relief and encouraging sleep.

In the context of the oxides group, these compounds are typically characterized by their chemical structure that includes ether, which can have pulmonary effects and beneficial properties for respiratory-related issues. German Chamomile fits this description well, establishing its role within this group.

Other choices, while beneficial in their own right, do not specifically belong to the oxides group or are not primarily known for calming properties as German Chamomile is. Hence, its unique combination of relaxing effects and belonging to the oxides group underscores why it is the correct answer in this scenario.