The question below consists of a set of six labelled sentences. They are all sentences of the same paragraph but their order has been jumbled. Sentence C given below is the third sentence in the correct order. Arrange the other five sentences in their correct order to make a coherent paragraph and answer the questions that follow:

A: The birds spent far more of their time - up to a third - pecking at the inanimate objects in the pens, in contrast to birds in other pens, which spent a lot of time attacking others.

B: Commercially reared chicken can be unusually aggressive and are often kept in darkened sheds to prevent them from pecking at each other.

C: Altering the bird's environment, by adding bales of wood-shaving to their pens, can work wonders.

D: In low light conditions, they behave less belligerently but are more prone to ophthalmic disorders and respiratory problems.

E: Bales could diminish aggressiveness and reduce injuries; they might even improve productivity since a happy chicken is a productive chicken.

F: In an experiment, aggressive head-pecking was all but eliminated among birds in the enriched environment.