Maintenance testing is a system done on various things including software and equipment. However, it does perform the same thing which is to see what is not working correctly. There are three different levels that can be performed and they are the system level, equipment level and the component level. There is a set of requirements that the object or equipment is supposed to do and if they don’t then a maintenance testing should be done first to determine what is not working.
During the performance of the maintenance testing, there are two testing methodologies that are adopted. These are called the breadth test and depth test. The breadth test refers to the testing that is done on an equipment in general and does not look at the details.
Breadth test and depth test-evaluating the options:
a) option a: breadth testing is a test suite that exercises the full functionality of a product but does not test features in detail. depth testing is a test that exercises a feature of a product in full detail.
b) option b: retesting is part of regression
c) option c: confirmation testing is a synonym for retesting
d) option d: sanity testing does not include full functionality
maintenance testing includes testing some features in detail (for e.g. environment) and for some features detail testing is not required. its a mix of both breadth and depth testing.
so, the answer is a