Which limitation is associated with form handlers?

The choice regarding the limitation associated with form handlers is that they cannot use dependent fields or progressive profiling. This is an important consideration when designing user forms for data collection.

Form handlers are designed to handle simple form submissions and are typically used to pass data from a web form directly to a marketing automation system. However, they lack the advanced feature set of full-fledged forms, which can include conditional logic, like dependent fields that change based on user input, or progressive profiling that gradually collects more information from users over time without overwhelming them.

In contrast, the other options present misconceptions about what form handlers can or cannot do. For instance, form handlers can integrate with various CRM systems to some extent; they do not require HTML coding for all functionalities since they can also work with pre-existing structured data; and, while handling data, the aspect of securing sensitive data is dependent on the system's overall data management compliance, not inherently tied to the limitation of form handlers specifically. Thus, option B correctly identifies a specific limitation of form handlers in contrast to the capabilities of more comprehensive form solutions.