Question

lena would like to be able to know her exact location on a map as she travels across the country. which technology would best help lena?
cb radio, because it uses hf radio waves
mri, because it uses magnets to produce a picture
radio telescope, because it captures radio waves from space
gps, because it uses satellites that provide position and velocity data

Explanation:

CB radio is for communication, MRI for medical imaging, radio - telescope for space observations. GPS uses satellites to determine location, which is what Lena needs.

Answer:

D. GPS, because it uses satellites that provide position and velocity data