Groups of individuals in a well-defined geographical area, sharing or competing for similar resources, having the potential to interbreed, are the characteristics of:

Populations

The correct answer is Option (3) → Populations 

• A population = group of individuals of the same species living in a defined geographical area, sharing/competing for resources, and having the potential to interbreed.
• Community = groups of different species living together in an area.
• Biomass = total mass of living matter.
• Organism = a single individual.