Option 1: This option states that an `Eco-mark` is a scheme for eco-friendly and cost-effective production technique. However, this is not the correct definition of an `Eco-mark`. An `Eco-mark` is not specifically related to the production technique or cost-effectiveness of a product, but rather focuses on the environmental friendliness of a consumer product.

Option 2: This option claims that an `Eco-mark` is a scheme for labeling pollution-free manufacturing units. While it is true that an `Eco-mark` is a labeling scheme, it does not specifically label manufacturing units. Instead, it labels consumer products based on their environmental friendliness.

Option 3: This option correctly identifies an `Eco-mark` as a scheme for labeling environment-friendly consumer products. An `Eco-mark` is a certification or label that indicates that a product has met specific environmental standards and is considered environmentally friendly. This label helps consumers identify and choose products that are less harmful to the environment.

Option 4: This option suggests that an `Eco-mark` is an international certification recognizing the eco-friendly and exportable quality of a product. While it is true that an `Eco-mark` is a certification, it is not specifically related to export