In a sample of 12 participants, a researcher estimates the 80% Confidence Interval for a sample with a mean of M = 22.3 and an estimated standard error (SM) of 4.7. What is the confidence interval at this level of confidence?
A. 80% CI 12.1, 32.5
B. 80% CI 17.6, 27.0
C. 80% CI 15.9, 28.7
D. Not enough information to answer