Economic activities refer to the activities that are undertaken by individuals or organizations to earn their livelihoods. These activities involve the production, distribution, and consumption of goods and services. The economic activities are essential for the growth and development of a country's economy. Some of the activities that fall under economic activities are:

1. Production: The process of creating goods and services by using various resources such as labor, capital, and land is known as production. This activity is carried out by businesses and individuals to earn a profit.

2. Trade: The exchange of goods and services between individuals or organizations is known as trade. It involves buying and selling of goods and services to earn a profit.

3. Services: The activities that involve providing services to customers are known as services. Services can be anything from healthcare to transportation.

4. Agriculture: Agriculture involves the production of crops, livestock, and other agricultural products. This activity is carried out by farmers to earn a livelihood.

5. Mining: Mining involves the extraction of minerals and other natural resources from the earth. This activity is carried out by mining companies to earn a profit.

6. Construction: Construction involves building structures such as buildings, bridges, and roads. This activity is carried out by construction companies to earn a profit.

In conclusion, economic activities are essential for the growth and development of a country's economy. These activities involve the production, distribution, and consumption of goods and services and are carried out by individuals and organizations to earn a livelihood.

Correct answer is Option 'a' . Economic activities are undertaken to earn a living as the name itself denotes activities performed in the economy for achieving economic objectives of profit , survival and growth of business( which includes industry, trade and commerce). So these are called the activities for earning livelihood for our family and for fulfilling other respective needs . Economic activities play a major role in economic development of a country along with non economic activities.