Answer: A. Usability testing
Explanation:
Usability testing would be the correct answer because if the user interface isn't "frendly" then people won't be able to use it properly. Or if you are refering to the word friendly as looking safe, then even more so would be usability testing. Because if people don't like the fonts and styles of the user interface, they might not use it at all.
Just select the fraction text and choose Open Type > Fractions from the Character panel menu.
I don't believe that there are rules.
Hope I helped,
Ms. Weasley
Explanation:
the objective of ITIL service operations is to make sure that IT services are delivered effectively and efficiently. the service operation life cycle stage includes the fulfilling of user requests, resolving service failure fixing problems and also carrying out routine operational tasks