Final answer:
Christophe was chasing rabbits in the field, as indicated by multiple passages in the story where the activity of pursuing rabbits is described.
Step-by-step explanation:
The beginning of the story indicates that Christophe was chasing rabbits in the field. This is clear from the passages where the presence of rabbits is repeatedly noted and the actions of Christophe and others involve pursuing rabbits. In one instance, the chase persists up a slope until he eventually captures the rabbit. These recurring scenarios show that rabbits are an integral part of the setting and activity within the story.