Final answer:
An increase in nodularity and tenderness of the breasts is most commonly associated with benign breast disease, though any changes should be monitored because they could also indicate breast cancer.
Step-by-step explanation:
An increase in nodularity and tenderness of the breasts can be indicative of several conditions, but within the provided options, it is most commonly associated with A) Benign breast disease. This condition includes various non-cancerous disorders such as fibrocystic breast changes, which can cause lumpiness and discomfort, often correlating with the menstrual cycle. However, it is critical to perform regular self-examinations, as lumps or other changes could signal breast cancer. Cyclic mastalgia is mostly related to pain with a clear relationship to the menstrual cycle without a significant increase in nodularity. Gynecomastia, an increase of breast tissue in males, does not fit the context of this question.