Before humans became systematic hunters or hunter/gatherers, they may have been:

a. carnivores (meat-eaters)

b. scavengers of meat and gatherers of plants

c. primitive horticulturists (growing plant foods)

d. primitive herdsmen (domesticating animals for food)

Answer: Option B.

Explanation:

Early humans obtained food via scavenging meat and gathering plants and hence earlier they are called scavengers.

During early ages before the evolution of hunting our ancestors, hominine rely on the food provided by nature through foraging or scavenging animals that are killed by other predators and gathering of plants and small animals, insects and birds.

However, some environmental changes induced variations in conditions, biodiversity, and resource availability, that affected interspecific interactions (environmental competition) over time that allowed evolution of hominines into homosapiens and developed their skill in hunting.

Hence, the correct option is B.