Which of the following is a risk factor for acute glomerulonephritis?

The correct answer is B: Recent streptococcal infection. Acute glomerulonephritis is often triggered by an immune response to a streptococcal infection. The bacteria's antigens can cross-react with glomerular antigens, leading to inflammation and damage to the kidneys. Genetic predisposition (A) may play a role in susceptibility, but the immediate trigger is the infection. High blood pressure (C) can be a consequence of glomerulonephritis, not a risk factor. Excessive fluid consumption (D) is not directly linked to the development of acute glomerulonephritis.