A senior software engineer starts working at a small company that wants to incorporate secure coding practices. Quality assurance currently begins after the application has been tested but before production. The engineer sees an opportunity and recommends adopting a method that breaks down the project into smaller biweekly development "bursts" that include testing. Which of the following statements are true? Select all that apply

a$.$ The engineer prefers using the agile model.

b$.$ The engineer is suggesting the iterative model.

c$.$ The engineer is advocating for the waterfall model.

d$.$ The company is currently using the waterfall model.

e$.$ The model suggested by the engineer uses a system that has sequential characteristics.