Answer:
Wild and out of control .
Something that is spreading or growing quickly .
Explanation:
The word "rampant" is an adjective that describes a scene or action. It means something that is fast spreading, quickly affecting the surrounding areas, or anything that is uncontrolled, unrestrained, or difficult to be contained put in order.
The sentence "[T]hey coped with knee-deep mud, with the sickening stench of garbage and human waste, with rampant disease, with constant fear" presents an image of a scene that is hard to comprehend or not normal. It is full of "mud . . . sickening stench of garbage and human waste . . . disease". And the use of the word "rampant" in describing the "disease" shows that the disease is fast spreading and difficult to be contained or controlled. This means that it is wild, growing, or spreading quickly.
Thus, the correct answers are the first and third options.