Which software development model is actually a meta-model that incorporates a number of the
software development models?

A.
The Waterfall model.

B.
The modified Waterfall model.

C.
The Spiral model.

D.
The Critical Patch Model (CPM).

Explanation:
The spiral model for software engineering has evolved to encompass the best
features of the classic waterfall model, while at the same time adding an element known as risk
analysis. The spiral model is more appropriate for large, industrial software projects and has four
main blocks/quadrants. Each release or version of the software requires going through new
planning, risk analysis, engineering and customer evaluation phases and this is illustrated in the
model by the spiral evolution outwards from the center. For each new release of a software
product, a risk analysis audit should be performed to decide whether the new objectives can be
completed within budget (time and costs), and decisions have to be made about whether to
proceed. The level of planning and customer evaluation is missing from the waterfall model which
is mainly concerned with small software programs. The spiral model also illustrated the
evolutionary development of software where a solution may be initially proposed which is very
basic (first time round the loop) and then later releases add new features and possibly a more
elaborate GUI.