ans should be A
Code-and-Fix------->Write some code, debug it, repeat (i.e. ad-hoc)
Evolutionary prototyping--->Build an initial small requirement specifications, code it, then “evolve” the specifications & code as needed
Spiral------>Assess risks at each step; do most critical action first.
staged delivery--->. Build initial requirement specification for several releases, then design-and-code in sequence
Waterfall --------->Standard phases (requirements, design, code, test) in order