Which statement is true regarding kidney stones?

Which statement is true regarding kidney stones?
  a. A high carbohydrate diet decreases the risk for their formation.
  b. A high carbohydrate diet increases the risk for their formation.
  c. A high protein diet increases the risk for their formation.
  d. A high protein diet decreases the risk for their formation
  e. A low protein and low fat diet increases the risk for their formation.

Question 2

Kidney problems can arise from ____.
  a. viral infections
  b. gall stones
  c. arsenic or lead poisoning
  d. low protein diets
  e. high protein diets