Which of the following is a requirement for corner markings in subdivision plans?

The requirement for corner markings in subdivision plans stipulates that they must be sized and flagged on each lot. This is crucial for establishing clear boundaries and ensuring that property lines are easily identifiable. Properly marked corners help prevent disputes between neighbors and assist in any future developments or modifications to the property. Flagging each corner visually denotes the boundaries and provides an important reference point for property owners and developers alike.

While the other options may involve different aspects of property development or planning, they do not directly pertain to the specific requirements for corner markings. For example, while it could be beneficial for corner markings to be painted in bright colors for visibility, this is not a mandatory requirement. Similarly, surveying by a licensed architect or recording in the county clerk's office applies to broader planning and legal processes, rather than the specific requirement regarding the corner markings of lots in a subdivision.