Identify, from among the following, the correct statement.
(a) One of the main challenges Software Engineering facing today is the requirement of most software systems to work with a multitude of homogenous systems
(b) 'Legacy systems' are custom developed software systems for the legal domain
(c) Software does not wear-out in the traditional sense of the term, but software does tend to deteriorate as it evolves
(d) Since software is essentially 'intangible' it is relatively easy to manage software projects
(e) With the advent of component based software assembly, we find that only less than 20% of today's software is still custom built.