A.I. Explanation:

Option 1: "To increase the sales of personal vehicles"

Explanation: This option contradicts the text, which states that the new transportation system aims to reduce reliance on personal vehicles. Therefore, increasing their sales is not aligned with the system's goals.

Option 2: "To offer a more expensive mode of travel"

Explanation: The text emphasizes providing a faster, more efficient, and eco-friendly way to travel, which implies affordability rather than increased costs. Thus, this option does not reflect the intent of the transportation system.

Option 3: "To limit access to certain city areas"

Explanation: The text highlights that the expanded subway network ensures greater accessibility to all city areas, making this option incorrect as it suggests the opposite of the intended goal.

Option 4: "To enhance urban mobility and sustainability"

Explanation: This option accurately reflects the primary goal of the transportation system as described in the text. The system aims to provide a more efficient and eco-friendly way to travel, which enhances urban mobility and aligns with sustainable development.