Answer:
d. Keeping the survey short makes it more likely people will be willing to complete it.
Step-by-step explanation:
Surveys are designed to collect primary (first hand) information, for conducting a research.
A good survey questionnaire has many features :- Apt length, short & simple questions, properly arranged questions, easy language etc.
The most important 'good questionnaire characteristic' is : The right length. It should not be too short, as to not cover the important aspects of research questions. It should not be too long, as a lengthy questionnaire negatively effects the length & quality of responses.