What Is One Reason Why a Study Investigating Whether a New

Multiple Choice

What is one reason why a study investigating whether a new urban housing assistance program reduces homelessness might not achieve internal validity?

A) At the same time of the study,developers flood the market with affordable apartments,making housing more accessible to homeless populations.
B) While the intervention may work in the city,urban participants might differ from homeless populations in a rural area.
C) Researchers received money from a foundation aimed to end homelessness,which might have a vested interest in the results.
D) Homeless populations are difficult to follow since they tend to move around so much.