The correct option is (b).
Explanation
Resources are broadly classified into natural, human-made, and human resources. Human-made resources are created when humans interact with natural substances and modify them using technology to create useful structures or tools.
Statement 1 is Incorrect:
Human-made resources are not used without modification. Natural resources (like air, water, or sunlight) might be used directly, but human-made resources exist only because the original form of a natural substance has been changed. For instance, iron ore is a natural resource, but it becomes a human-made resource only after extraction and processing.
Statement 2 is Correct:
Buildings, bridges, roads, machinery, and vehicles are prime examples of human-made resources. Humans use natural resources (such as stone, timber, and metals) to construct these infrastructures to satisfy specific needs.
Statement 3 is Incorrect:
The defining characteristic of human-made resources is that they are created by altering the original form of natural substances. Without this modification or processing through technology, the substance remains a natural resource.
Key Takeaway:
Human-made resources are natural resources that have undergone value addition and physical modification through human skill and technology (e.g., turning wood into furniture or iron ore into bridges).