A woman is experiencing back labor and complains of intense pain in her lower back.
An effective relief measure would be to use:

Choice A rationale

Supine hypotension, or aortocaval compression, is a risk typically associated with lying flat on the back during late pregnancy or labor, which compresses the vena cava and aorta. Rupture of membranes does not directly or significantly increase this risk; proper positioning, such as left lateral tilt, prevents this complication.

Choice B rationale

Precipitous labor is characterized by rapid labor and birth occurring within three hours of the onset of contractions. While rupture of membranes can occasionally precede or be associated with rapid progression, it is not an independent factor that substantially increases the underlying risk of a woman having a precipitous labor.

Choice C rationale

Intrauterine infection, or chorioamnionitis, is the primary risk that increases significantly after rupture of membranes, particularly if labor is prolonged. The amniotic sac provides a sterile barrier; its loss allows bacteria from the vagina to ascend into the uterus, which can infect the mother and the fetus.

Choice D rationale

Hemorrhage, or excessive bleeding, is most often associated with uterine atony, retained placental fragments, or trauma following birth. Rupture of membranes is not a direct or strong predictor of postpartum hemorrhage; this complication is primarily related to the third and fourth stages of labor.

Choice A rationale

Urinary frequency is a presumptive sign of pregnancy often caused by hormonal changes, particularly increased human chorionic gonadotropin (hCG) and progesterone, and pressure from the enlarging uterus on the bladder, leading to a reduced bladder capacity and increased renal blood flow and filtration rate.

Choice B rationale

A positive urine pregnancy test is a probable sign of pregnancy, as it is highly suggestive but not entirely conclusive. It detects the presence of human chorionic gonadotropin (hCG), which can also be elevated due to certain tumors or conditions other than a viable intrauterine pregnancy.

Choice C rationale

Breast changes, such as fullness, tenderness, and darkening of the areolae, are presumptive signs. These changes are stimulated early in pregnancy by elevated levels of estrogen and progesterone, preparing the mammary glands for lactation and causing vascular engorgement and glandular hyperplasia.

Choice D rationale

Quickening refers to the maternal perception of fetal movement, usually felt between 16 and 20 weeks gestation. Because it is a subjective sensation, it is classified as a presumptive sign; it could potentially be confused with peristalsis or gas in the abdomen.

Choice E rationale

Amenorrhea, the cessation of menstruation, is an early and very common presumptive sign of pregnancy. It is caused by the hormonal milieu, primarily the sustained production of progesterone by the corpus luteum, which prevents the shedding of the endometrial lining.