Information radiators are a key communication tool in Agile and adaptive environments. They are visual displays of project information (e.g., task boards, burn-down charts) that are constantly updated and visible to all stakeholders. They promote transparency, immediate access to project status, and facilitate self-organizing teams. The Agile Practice Guide specifically recommends the use of information radiators as a best practice to facilitate rapid and visible communication. Option A (pull communication) requires users to seek out information but doesn't promote transparency. Option B (push communication) is useful but not as effective in agile environments for real-time visibility. Option C is incomplete-verbal techniques are informal and limited in accessibility. Reference: Agile Practice Guide, Section 5.5.1 - Information Radiators PMBOK Guide - Seventh Edition, Communication Performance Domain -