Final answer:
The questionnaire that Gerald has prepared for his research on consumer behavior is typically using a dichotomous question type.
Step-by-step explanation:
The questionnaire that Gerald has prepared for his research on consumer behavior is typically using a dichotomous question type. The questions in his survey allow respondents to answer in either a 'Yes' or a 'No'. In a dichotomous question, respondents are provided with only two response options, making it suitable for simple, straightforward questions like those in Gerald's survey.