According to standard graphic design principles, which of the following is an essential quality of an effective logo?

### Why this is right - **Usability when enlarged or reduced** is named directly as a requirement for retaining distinctive characteristics across sizes. - **Versatility across digital, print, and other materials** reflects the proposal's requirement that the logo adapt to different applications. - **Uniqueness that helps the logo stand out from competitors** is the proposal's stated meaning of uniqueness. ### The concept These criteria examine different aspects of a logo. Usability concerns scaling, versatility concerns applications, and uniqueness concerns distinction from competitors. Identifiability and the one-colour test are additional criteria in the proposal. Together, they help assess whether a logo can be recognized and used in the ways the brand needs. They should not be collapsed into a single test because each addresses a different design problem. ### The other options - **D. Dependence on colour to distinguish key features**: The proposal rejects relying on colour alone; the logo should retain its characteristics in one colour. ### Terms - **Identifiability**: The quality of being simple to recognize and remember. ### Remember Keep the tests distinct: size, application, differentiation, recognition, and one-colour communication.