Final answer:
Recurrent vomiting causes metabolic alkalosis, which is characterized by decreased potassium (hypokalemia), decreased chloride (hypochloremia), and an increased pH.
Step-by-step explanation:
Recurrent vomiting primarily leads to metabolic alkalosis due to loss of hydrogen and chloride ions from the stomach. As a result, there is a decrease in serum potassium (hypokalemia) and chloride (hypochloremia). These electrolyte imbalances shift the body's pH towards alkalosis; hence, pH increases. In an attempt to compensate, the kidneys may conserve hydrogen ions and excrete potassium, further reducing serum potassium levels. Additionally, hypokalemia can cause the renal tubules to exchange potassium for hydrogen ions, contributing to further alkalosis.
Given this information, the correct answer to the student's question - Recurrent vomiting has what effect on the following labs? K+, Cl-, pH - would be C. Decreased K+, increased Cl-, increased pH. However, this answer choice incorrectly indicates an increase in Cl-, which should actually be decreased, demonstrating that there is likely a typographical error in the answer choices. Considering the physiological effects of recurrent vomiting, the accurate response should be: decreased K+, decreased Cl-, increased pH.