Choosing a Size for the Classic Shirt

Hi Everyone, I purchased the Classic Shirt pattern today and I'm excited that it's available in different cup sizes, however I'm at a loss as to how to choose the right size for my first muslin. My upper bust is 37", full bust is 40", waist 34", hips 43". According to the pattern chart, this means I'm a straight size 14. I'm assuming the pattern chart is also based off a standard B cup (2" difference) block, but according to my FB-UB measurement, I'm a C cup, and my shoulders would be too small for a standard size 14. Where in the instructions can I see how to choose the right size for me?