Sleep apnea is a disorder in which you have one or more pauses in breathing or shallow breaths while you sleep. In a cross-sectional study of 370 adults who suffer from sleep apnea, it was found that 222 had gum disease. Note: In the general population, about 17.5% of individuals have gum disease. Complete parts (a) through (c) below. Click here to view the standard normal distribution table (page 1). Click here to view the standard normal distribution table (page 2). Click here to view the table of critical t-values, (a) What does it mean for this study to be cross-sectional? A. The data were obtained over the course of time and the study was an experiment. O B. The data were obtained at a specific point in time and the study was an observational study. O C. The data were obtained at a specific point in time and the study was an experiment. O D. The data were obtained over the course of time and the study was an observational study. (b) What is the variable of interest in this study? Is it qualitative or quantitative? Explain, Identify the variable of interest. Choose the correct answer below. O A. The proportion of gum disease present in those with sleep apnea. O B. Whether a person has sleep apnea or not. O C. Whether a person has gum disease or not. D. Whether a person with sleep apnea has gum disease or not. Determine whether the variable in question is qualitative or quantitative. Choose the correct answer below. A. Quantitative-the variable can be numerically measured. O B. Qualitative-the variable classifies the individuals in the study. O C. Qualitative-the variable can be numerically measured. D. Quantitative-the vanable classifies the individuals in the study