Eliza Takes Care to Illustrate in Her Research Report How

Eliza takes care to illustrate in her research report how long she was in the field and how she has minimized observer effects.
-Ai-mu conducted a study on recent immigrants' opinions of schools in America. She is careful to report her training and abilities to conduct the research in her manuscript. By so doing, Ai-mu is specifically addressing

A) threats to internal validity.
B) threats to external validity.
C) reliability.
D) ethics concerns