Following surgery for pyloric stenosis, an infant should be burped well following feedings primarily to prevent:

A. Breast tenderness: Breast tenderness is a common early sign of pregnancy due to hormonal changes, particularly increased estrogen and progesterone. It is a presumptive sign because it is not unique to pregnancy and can occur with other conditions as well.

B. Amenorrhea: Amenorrhea, or the absence of menstruation, is one of the most common early signs of pregnancy. It is considered presumptive because it can also be caused by other factors such as stress, illness, or hormonal imbalances.

C. Frequent urination: Frequent urination occurs due to hormonal changes and increased blood volume, which leads to more fluid being processed by the kidneys. It is considered a presumptive sign of pregnancy, though it can also occur with other conditions like urinary tract infections.

D. Positive pregnancy test: A positive pregnancy test detects the hormone human chorionic gonadotropin (hCG), which is a probable sign of pregnancy. It is more definitive than a presumptive sign, but it can sometimes result in false positives due to certain medications or other conditions.

E. Chadwick sign: Chadwick's sign, characterized by the bluish tint of the cervix, vagina, and vulva due to increased blood flow, is a probable sign of pregnancy. It is typically observed by a healthcare provider during a physical examination and suggests pregnancy but is not definitive.

F. Quickening: Quickening is the feeling of fetal movement, which typically occurs between 18 and 20 weeks of pregnancy for first-time mothers. It is a presumptive sign because other conditions, such as gas or muscle spasms, can cause similar sensations.

A. "Your baby is making urine so this is adding to what's in your bladder.": While the baby does produce urine, it is not stored in the mother's bladder. The baby’s urine is filtered through the placenta and into the amniotic fluid, not contributing directly to the mother's urinary frequency.

B. "Your kidneys now have less cells to filter the fluid that goes through": Pregnancy increases kidney function. The kidneys filter more blood and produce more urine to accommodate the increased blood volume in the body, but frequent urination is not due to fewer cells.

C. "Your growing uterus is putting pressure on your bladder causing you to go": During early pregnancy, the growing uterus starts to exert pressure on the bladder, which leads to increased frequency of urination. This is a common and normal symptom during pregnancy.

D. "Your urine is more concentrated now, so you have to go more often": Pregnancy does not cause urine to be more concentrated, but rather it increases the volume of urine due to the increased blood volume and kidney function. The frequency is due to pressure on the bladder, not changes in urine concentration.