Which If the Following Most Closely Represents the US Department

Which if the following most closely represents the US Department of Health and Human Services' definition of research?

A) A systematic investigation, including research development, testing and evaluation, designed to develop or contribute to generalizable knowledge
B) A focused examination of a set of questions, with the overall goals to expand human kind's knowledge of a particular topic area that may or may not have immediate and practical ramifications.
C) A broad set of questions set out to serve the betterment of society
D) A continuing expansion of knowledge through systematic experiments and testing to maximize efficiency in human behavior and output.