Consider taking random samples of size 50 from Population A with mean 15 and standard deviation 3 and random samples of size 75 from Population B with mean 10 and standard deviation 5. a. Find the mean of the distribution of differences in sample means A) -5 B) 5 C) 10 D) 15 b. Find the standard error of the distribution of differences in sample means A) 0.1267 B) 0.3559 C) 0.5133 D) 0.7165 c. How many degrees of freedom should be used when conducting inference tests with samples of this size? A) 49 B) 50 C) 74 D) 75