Builder Design pattern

Compact Computers is a small computer assembly company. Their online application allows customers to pick and choose accessories to build their own PCs. The accessories are:

i. Processor - 800Mhz, 1Ghz, 1.2Ghz

ii. HDD - 40 GB, 60 GB, 80 GB

iii. Memory - 128 MB, 256 MB, 512 MB

If a computer can have exactly 1 processor, 1 HDD and 1 memory stick, what pattern would be best used here?

A Factory Method

B Builder

C Prototype

D Abstract Factory

E Singleton

Can somebody please explain why it the answer is Builder ?

I am sure you can understand why it needs to builder if see the example @

http://www.dofactory.com/Patterns/PatternBuilder.aspx

Satheesh

We should use the builder pattern here for the following reasons.

a) To separate the construction process of the computer from its representation. This gives us the better control to keep the assembling process separately from the end object type.

b) Because we need to assemble several kinds of computer propreties objects like CPU, Monitor etc but result in a different object type (like ComputerModel based on assembled properties).

Example: http://www.c-sharpcorner.com/Code/2002/Feb/CreationalPatternBuilderAJ.asp

Regards,
Kiran.