List the task regions in the Spiral model. 

Customer communication - In this region it is suggested to set up customer communication. 

Planning - All planning activities are carried out in order to explain resources timeline and other project related activities. 

Risk analysis - The tasks needed to calculate technical and management risks.

Engineering - In this the task region, tasks needed to build one or more representations of applications are carried out. 

Construct and release - All the essential tasks required to construct, test, install the applications are conducted. 

Customer evaluation - Customer's feedback is attained and based on the customer evaluation required tasks are performed and executed at installation stage