How long is the highway mentioned in the content?

The choice indicating the highway is about 150 kilometers is correct because that aligns with the information provided in the content. This specific length offers a clear and precise measurement, suggesting that the highway is of considerable length, making it significant for travel and logistics. The other options either underestimate or overestimate the distance of the highway, failing to accurately reflect the details presented in the content. For instance, stating the highway is approximately 100 kilometers would imply a shorter distance that may not capture its full extent, while labeling it as nearly 200 kilometers or less than 50 kilometers provides inaccurate assessments that diverge from the stated information.