A.I. Explanation:

Option 1: "To reduce production costs"

Explanation: This option is incorrect because the text does not mention reducing production costs as a goal of sustainable fashion. Instead, it emphasizes environmental consciousness and ethical practices. The focus is on eco-friendly materials and reducing the carbon footprint, not on cost reduction.

Option 2: "To increase brand popularity"

Explanation: This option is incorrect as the text does not discuss increasing brand popularity. The main focus is on the environmental impact and ethical practices associated with sustainable fashion, rather than marketing or brand recognition.

Option 3: "To reduce the fashion industry's environmental impact"

Explanation: This option is correct because the text explicitly states that sustainable fashion aims to reduce the fashion industry's carbon footprint and environmental impact. It highlights the use of eco-friendly materials and practices that contribute to this goal, making it the main idea of the text.

Option 4: "To speed up the manufacturing process"

Explanation: This option is incorrect because the text does not mention speeding up the manufacturing process as a goal of sustainable fashion. Instead, it focuses on using less water-intensive processes and eco-friendly practices, which may not necessarily correlate with faster manufacturing.