FROM THE CASP STUDENT GUIDE.. C & D ARE CORRECT.. READ PEOPLE:
Agile Model
The more recent Agile model uses iterative processes to release well-tested code
in smaller blocks or units. In this model, development and provisioning tasks are
conceived as continuous. This method focuses on adaptive measures in various phases—such as requirements—so that development teams can more easily collaborate and
respond to changes. The agile method breaks up tasks incrementally, so that there
is no long-term planning, but only short iterations that developers can more easily
alter to fit their evolving needs. At the end of each iteration, developers present
their progress to clients and other stakeholders to receive feedback and input that
they can use in proceeding iterations. The agile method is particularly useful in
complex, unstable systems whose requirements and design are not easy to predict. The agile modelʼs focus on rapid development often undermines security. Developers release rapidly which can introduce new, untested functionality
and vulnerabilities.