Final answer:
The most suitable control for a Yes/No field on a form is a checkbox because it provides a clear indication of a selection between two mutually exclusive options.
Step-by-step explanation:
The most appropriate control for displaying a Yes/No field on a form would be a checkbox. When there are only two mutually exclusive options to choose from, checkboxes and radio buttons are usually preferred. A checkbox is ideal for representing a single Yes/No option, as it clearly indicates whether the option is selected (Yes) or not selected (No). A dropdown could be used but is less efficient for only two options, while a textbox is more suitable for open-ended responses. Radio buttons could also work well, especially if the design calls for clearly displaying both the Yes and No options side by side for the user to select one.