The Spiral Model of the software development process (B.W. Boehm, A
Spiral Model of Software Development and Enhancement, IEEE
Computer, May, 1988) uses the following metric relative to the spiral:

A.
The angular dimension represents cumulative cost

B.
The radial dimension represents cumulative cost

C.
The radial dimension represents progress made in completing each
cycle

D.
The radial dimension represents the cost of each phase

Explanation:
The radial dimension represents cumulative cost and the angular
dimension represents progress made in completing each cycle of the
spiral. The spiral model is actually a meta-model for software development
processes. Asummary of the stages in the spiral is as follows:
The spiral begins in the top, left-hand quadrant by determining the
objectives of the portion of the product being developed, the
alternative means of implementing this portion of the product, and
the constraints imposed on the application of the alternatives.
Next, the risks of the alternatives are evaluated based on the
objectives and constraints. Following this step, the relative
balances of the perceived risks are determined.
The spiral then proceeds to the lower right-hand quadrant where
the development phases of the projects begin. A major review
completes each cycle and then the process begins anew for
succeeding phases of the project. Typical succeeding phases are
software product design, integration and test plan development,
additional risk analyses, operational prototype, detailed design,

code, unit test, acceptance test, and implementation.
The other answers are distracters.