Consider the following factors regarding an industry:

Correct Option (b)

Capital investment (1) represents the financial resources deployed in an industry, including expenditure on land, machinery, and infrastructure. It directly influences the production capacity and overall scale of operations, thereby determining the industry's size. Business turnover (2) indicates the total value of sales or revenue generated, serving as a direct measure of the volume of goods and services produced and sold, which is a key indicator of both the size and economic activity of the industry. Power consumption (4) reflects the operational intensity and technological requirements. High power consumption often characterizes heavy industries or those with continuous process operations, thus indicating the nature and scale of industrial activity. These three factors collectively provide a comprehensive understanding of an industry's operational scale, economic contribution, and resource intensity, which are crucial for defining its nature and size.

Incorrect Options:

• Option (a) (1, 3 & 4): This option excludes business turnover (2). Business turnover is a critical metric for assessing the economic scale and output of an industry, making its exclusion incomplete for determining nature and size.
• Option (c) (2, 3 & 4): This option omits capital investment (1). Capital investment is fundamental to establishing the production capacity and overall scale of an industry, and its absence would lead to an incomplete assessment of the industry's size and nature.
• Option (d) (2 & 3): This option excludes both capital investment (1) and power consumption (4). Both are essential structural and operational indicators that define an industry's scale, technological intensity, and resource requirements, making this option insufficient.