Final Answer:
The term that describes the phenomenon where those who do respond to questionnaires are likely different from those who do not is A) Nonresponse.
Step-by-step explanation:
Nonresponse occurs in survey research when individuals chosen for the study do not participate or provide incomplete responses. This can introduce bias because the characteristics of those who choose not to respond may differ systematically from those who do respond. The result is a potential distortion of the survey findings, impacting the generalizability of the results to the entire population.
Options B, C, D, and E do not specifically address the concept of differences between respondents and non-respondents. Nonresponse is a critical consideration in survey methodology, and researchers often use various strategies to mitigate its impact and ensure the validity of survey results.
Option A is the answer.