Based on the Following Description

Multiple Choice

based on the following description:
A team of researchers is interested in the way children's self-esteem changes during puberty and how it relates to parental warmth. They are particularly interested in how self-esteem changes within individuals over time. They recruit a sample of 50 11-year-olds and plan to examine them for the next 6 years.
-Which of the following is not a challenge that the researchers are likely to face?

A) Working around subject attrition
B) Mitigating the influence of repeated testing
C) Having trouble determining processes of change
D) Effectively maintaining research personnel over time