Chicken Aggression Environment Alteration

Sentences given in each question, when properly sequenced, form a coherent paragraph. The first and last sentences are 1 and 6, and the four in between are labelled A,B,C and D. Choose the most logical order of these four sentences from among the four given choices to construct a coherent paragraph from sentences 1 to 6.

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

1. 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.
2. In low light conditions, they behave less belligerently, but are more prone to ophthalmic disorders and respiratory problems.
3. In an experiment, aggressive head-pecking was all but eliminated among birds in the enriched environment.
4. Altering the birds’ environment, by adding bales of wood-shavings to their pens, can work wonders.

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