A Contraceptive That Does Not Contain Estrogen Has Been Recommended

A contraceptive that does not contain estrogen has been recommended for a client with a history of deep vein thrombosis,but the client does not know why.Which statement by the nurse best explains the relationship of estrogen to thromboembolic events?

A) Estrogen causes the bone marrow to form more red blood cells,which then increase the chance of blood cells clumping together and forming a clot."
B) Estrogen increases vascular vasoconstriction,which restricts blood flow and increases the opportunity for blood clots to form."
C) Estrogen causes several clotting factors to increase in the blood,which increases the chances of a blood clot occurring."
D) Estrogen decreases the force of blood flowing through the blood vessels,which increases the chances of blood clot formation."