What category refers to aspects that cannot be seen or are hidden from view?

The correct answer refers to aspects that cannot be seen or are hidden from view, which aligns with the notion of something being non-viewable. This term captures the essence of being entirely obscured or not able to be perceived by the human eye or through observation.

Using this term emphasizes the totality of the hidden nature of the aspects in question, denoting that there is an absence of visibility in any form. This clarity in terminology allows for precise communication, particularly in contexts where the distinctions between what is visible and what is not are critical, such as in casualty assistance scenarios where understanding the visibility of information can impact decision-making and support.

Other options may suggest partial visibility or limited visibility, which does not fully encapsulate the idea of complete absence from view, thereby making them less accurate in describing aspects that are entirely hidden.