Sentence Correction

Pls explain the difference between choice (C) and (D):

When one eats in this restaurant, you often find that the prices are high and that the food is poorly prepared.
(A) When one eats in this restaurant, you often find
(B) When one eats in this restaurant, one often finds
(C) As you eat in this restaurant, you often find
(D) If you eat in this restaurant, you often find
(E) When one ate in this restaurant, he often found