Table 1 shows the characteristics of 4 students that signed up for a Business Intelligence (BI) course. Gender is student's gender. Previous Bl experience indicates whether the student has taken any BI classes before which is a binary variable where 1 represents "yes, student has taken a BI class before", and 0 represents "no, student has not taken any BI classes before". Co-major is student's co-major. Age is student's age in years. Senior indicates whether or not a student is a senior. It is a binary variable where 0 represents "no, student is not a senior" and 1 represents "yes, student is a senior." Table 1. Student characteristics Gender Previous BI Co-Major Age Senior Experience Male Econ 119 Male Finance 20 Female Marketing 21 Female Marketing 25 Question 1: How many variables (columns) in Table 1 are categorical? QUESTION 2 Data shown in Table 1 is an example of data. O A. supervised O B. unsupervised O C. structured O D. unstructured QUESTION 3 In a facility, products are manufactured on an assembly line. Assume we count the number of products manufactured per day, and we visualize the frequency distribution of the number of manufactured products per day. The visual we would use for this purpose is a O A. Boxplot O B. Scatter plot O C. Time series O D. Histogram