Option 1: Trade Unions - This refers to organizations formed by workers to protect and promote their rights and interests in the workplace. Trade Unions are indeed included in the concurrent list. The concurrent list consists of subjects on which both the central government and state governments can make laws. This means that both the central and state governments have the power to regulate trade unions and their activities.

Option 2: Agriculture - While agriculture is an important sector, it is not specifically included in the concurrent list. Agriculture is primarily a state subject, meaning that the state governments have the authority to make laws and regulations related to agriculture.

Option 3: Tolls - Tolls are the fees charged for using certain roads, bridges, or highways. However, tolls are not included in the concurrent list. Tolls are typically regulated by the state government or local authorities.

Option 4: Markets and Fairs - Similarly, markets and fairs are also not included in the concurrent list. These are usually regulated by state governments or local authorities.