Question

1. how did measuring longitude help explorers during long - distance travel?

a. it eliminated the need for river - based trade routes
b. it allowed for more accurate long - distance navigation
c. it showed explorers where native tribes were located
d. it helped mapmakers draw cities and inland borders

Explanation:

Longitude measurement is crucial for navigation. It helps in determining the east - west position on the Earth's surface. Accurate longitude knowledge allows explorers to plot their course more precisely over long distances. Option a is incorrect as longitude measurement has no direct relation to eliminating river - based trade routes. Option c is wrong because longitude does not specifically show where native tribes are located. Option d is also incorrect as longitude measurement is more about navigation for explorers rather than directly helping map - makers draw cities and inland borders.

Answer:

B. It allowed for more accurate long - distance navigation