The question below consists of a set of labelled sentences. Out of the four options given, select the most logical order of the sentences to form a coherent paragraph.
The causes and their
X-in the same series Y-one order, they stand Z-effects belong to the
Software testing is verifying if a software meets the customer's requirements; if it has high quality; if it is bug free and if it is fit for use. Testing is important because it ensures that the product delivered is defect free which in turn emphasizes higher quality and proves to be cost effective.