Which of the following is NOT a type of turnstile?

The classification of turnstiles is based on their design and function in controlling access, particularly in security contexts. Full-height turnstiles are designed to provide maximum physical security, allowing only one person to pass at a time and preventing unauthorized entry. Waist-high turnstiles offer a balance of security and accessibility but do not prevent individuals from climbing over them. Optical turnstiles utilize sensors and sometimes a barrier that opens when a person is detected, enabling a smooth and efficient entry while still maintaining a level of control.

Automated turnstiles, while often used in the context of security, refer more generally to a category that includes mechanisms that operate automatically to manage access. However, automated turnstiles are not a distinct type of turnstile in the conventional classification system, which primarily focuses on physical characteristics and barriers. This distinction clarifies why automated turnstiles would not fit neatly into the recognized types, making it the correct response to the question.