When filling out a form, how can you tell the field is required?

• A. Field is outlined in red
• B. Field is outlined in blue
• C. Field is filled automatically
• D. Field has a star icon

Answer: (A)

Visual cues around a field are what tell you it must be filled out. A red outline around a field signals that input is required before you can proceed, making it the most direct and noticeable indicator in this form context. Blue outlines typically indicate focus or another state, a field filled automatically shows pre-population rather than necessity, and a star icon is used in some systems but isn’t the cue shown here. So, the red outline is the clearest signal that a field is mandatory.