Which law indicates that the markup of a bill is usually open to the public?

The Sunshine Law is designed to promote transparency in government by ensuring that meetings and decision-making processes are accessible to the public. Specifically, when it comes to the markup of a bill, the Sunshine Law mandates that such proceedings must be open to public observation. This means that citizens have the right to attend and observe the discussions and modifications that occur during the legislative process. This open access is crucial for maintaining accountability and ensuring that the actions of lawmakers are subject to public scrutiny.

The other options do touch on aspects of government transparency but in different contexts. The Freedom of Information Act primarily deals with the public's right to access federal agency records, while the Transparency in Legislation Act, although related to legislative processes, is not as widely recognized or as comprehensive in guaranteeing public access as the Sunshine Law. Meanwhile, the Public Access to Government Documents Law focuses more on ensuring availability of documents rather than the public nature of legislative markups. Thus, the Sunshine Law stands out as the specific legislation that relates directly to the public access of bill markups.