Suppose the Method of Tree Ring Dating Gave the Following $\quad$

Suppose the method of tree ring dating gave the following dates A.D. for an archaeological excavation site. Find an 80% confidence interval for the mean of all tree ring dates from this archaeological site.
1273 $\quad$ 1231 $\quad$ 1173 $\quad$ 1228 $\quad$ 1191 $\quad$ 1206 $\quad$ 1194 $\quad$ 1227 $\quad$ 1261

A) 1205.3 to 1234.9
B) 1205.3 to 1235.8
C) 1206.0 to 1235.8
D) 1205.1 to 1235.8
E) 1205.3 to 1235.6