Chocolate bars produced by a certain machine are labeled with 8.0 oz. The distribution of the actual weights of these chocolate bars is normal with a mean of 8.1 oz. and a standard deviation of 0.1 oz. A chocolate bar is considered underweight if it weighs less than 8.0 oz. Use z-scores to answer the following questions.

A. What proportion of chocolate bars weighs less than 8.0 oz.?

B. What proportion of chocolate bars weighs between 8.2 and 8.3 oz.?

C. How should the chocolate bar wrappers be labeled so that only 1% of such bars are underweight?