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.