Under what condition does the blind stop not exist?

The blind stop refers to the part of a window that is used to hold the window sashes in place. It is typically found in single-hung or double-hung windows. The correct answer indicates that the blind stop does not exist when there is no storm window frame, which implies that the structure supporting the window sashes is not in place.

Without a storm window frame, there is no structural element to hold the sashes securely, which means the blind stop wouldn't be functional or present. In the absence of this frame, the window system may not operate effectively, potentially compromising the window's ability to maintain containment against outside elements.

In contrast, the conditions of the other options either present situations where the blind stop would still function (like when the window is closed or opened) or involve scenarios (like a storm window frame) that imply the presence of the blind stop mechanism. Understanding these conditions assists in recognizing the structural elements involved in window systems and their implications for lead assessments and inspections.