Grandma Gertrude's Chocolates, a family owned business, has an opportunity to supply its products for distribution through a large coffee house chain. However, the coffee house chain as certain specifications regarding cacao as it wishes to advertise the health benefits ( antioxidants) of the chocolate products it sells. Past data indicate a standard deviation of 4%. If quality control inspectors wish to estimate the % cacao to within 1% of the true mean with 95% confidence, how many pieces of chocolate should they sample?
a. 36
b. 54
c. 29
d. 62
e. 89