What are the key lifecycle stages for reliable IT service delivery?

A.
service definition, proof of concept, development, and implementation

B.
investigate, innovate, implement, and improve

C.
requirements gathering, design, release and support, underpinned by change management

D.
plan, do, check, and act

Explanation:
Reference:http://www.itgo.nl/uploads/images/pdf/HP%20BTO_Good%20to%20great_Transform%
20your%20IT%20through%20service%20lifecycle%20management.pdf(page 5, optimize business
outcomes)