Which of the following can increase breast cancer risk related to our exposome?

The correct answer highlights the role of certain exposures in activating the estrogen receptor, which is directly linked to breast cancer risk. Estrogen receptors are proteins within cells that, when activated by estrogen, can promote cell growth and division. If certain exposures induce the activation of these receptors—even in the presence of lower overall estrogen levels—they can still stimulate cellular mechanisms that may lead to the development or progression of breast cancer.

In contrast, the other options suggest mechanisms for reducing breast cancer risk. Exposures that lower estrogen production or aromatase activity would likely decrease the levels of estrogen available to stimulate the estrogen receptors, consequently reducing the potential for receptor activation and thereby lowering the risk of breast cancer.