Which of the following examples represents correct hyphenation?

The correct answer is that all provided examples represent correct hyphenation. In APA style, hyphenation is employed to link words that work together as a single descriptor or modifier for a noun, enhancing readability and clarity.

"Randomly-assigned participants" correctly uses a hyphen to link "randomly" and "assigned,” indicating that the participants were assigned in a specific way. This clarifies the nature of the assignment, which is important for understanding the study's design.

"Higher-scoring students" also conforms to hyphenation rules, as it connects "higher" and "scoring" to describe students who score at a higher level. The hyphen helps emphasize that the two words function together as a descriptive unit.

"Self-report technique" uses a hyphen in accordance with APA guidelines, where "self-report" acts as a compound adjective that describes the technique used for data collection. This clarity is vital in academic writing to ensure that readers can easily comprehend the methodology being discussed.

Therefore, all options given correctly demonstrate how to use hyphenation in contexts relevant to research and academic writing, making D - "All of the above" the most accurate choice.