The distribution of the length of bolts has a bell-shaped distribution with a mean of 4 inches and a standard deviation of 0.007 inch. Answer the following question based on the empirical rule. What percentage of bolts manufatured will be between 4.007 inches and 4.021 inches?
(A)18.50%
(B)16%
(C)15.85%
(D)18.55%
(E)15.58%