Question 1182727
The confidence interval is {{{(X-bar) +- z[0.995]*(s/sqrt(n))}}}.

From the data given, 

{{{(X-bar) +- z[0.995]*(s/sqrt(n)) = 98.3 +- 2.576*(0.69/sqrt(108))}}}

= [98.13, 98.47].

98.6 degrees F is outside this interval on the right side, and so the answer is 

C. This suggests that the mean body temperature is significantly lower than 98.6°F.