Random sampling: Among all the objects to be examined, randomly sampling several objects for research, and using these objects to estimate the overall situation, this method is called random sampling. Which of the following is randomly sampled? ["Estimate the height of middle school students by measuring the height of 180 men's basketball and volleyball team members in juvenile sports schools.", 'Estimating the per capita income of any county (district) in each city of Fujian Province to estimate the per capita income of Fujian Province.', 'Estimating the per capita income of Fujian Province using the per capita income of Fuzhou.', 'Use the academic qualifications of college teachers to estimate the level of education in Fujian.']