Which of the following Viewport Property determines whether the display can be zoomed in and out?

The correct answer is: D. user-scalable

The user-scalable viewport property determines whether the display can be zoomed in and out. It can be set to yes or no. If it is set to yes, users can zoom in and out of the page using the mouse wheel or by pinching and zooming on touch devices. If it is set to no, users cannot zoom in and out of the page.

The scale and set-scale viewport properties are deprecated and should not be used. The adjust-scale viewport property is used to specify the minimum and maximum scale factors that can be applied to the page. It is not used to determine whether the page can be zoomed in and out.

Here is a more detailed explanation of each option:

• A. scale The scale viewport property is deprecated and should not be used. It specifies the initial scale factor of the page. The scale factor is the ratio of the size of the page on the screen to the size of the page in its original layout.
• B. set-scale The set-scale viewport property is deprecated and should not be used. It specifies the maximum scale factor that can be applied to the page.
• C. adjust-scale The adjust-scale viewport property is used to specify the minimum and maximum scale factors that can be applied to the page. It is not used to determine whether the page can be zoomed in and out.
• D. user-scalable The user-scalable viewport property determines whether the display can be zoomed in and out. It can be set to yes or no. If it is set to yes, users can zoom in and out of the page using the mouse wheel or by pinching and zooming on touch devices. If it is set to no, users cannot zoom in and out of the page.