Which of the following describes passive data entry systems in stability instruments?

In the context of stability instruments, passive data entry systems specifically refer to those that require manual data entry. This means that the user must input the necessary information and data manually, rather than the system automatically collecting and processing that information.

Manual data entry can often involve inputting parameters such as vessel dimensions, weights, and other stability factors that are critical for calculating the stability of a vessel. This process is usually prone to human error, leading to potential inaccuracies in stability calculations if the data is not entered correctly.

In contrast, systems that automatically read sensor data, provide real-time updates and alerts, or focus solely on software calculations, do not fit the characteristics of passive data entry systems. These alternatives indicate a more dynamic interaction and automated data processing, which is contrary to the manual nature of passive systems. Thus, the description of systems that require manual data entry accurately identifies the essence of passive data entry systems in stability instruments.