Which is an example of technology leading to a new discovery? A. A truck is used to ship goods between two states.
B. A telescope shows that there is a planet past Neptune
C. An irrigation system is installed at a farm.
D. An antibiotic is used to treat an infection.​

I think the answer would be B, because there is still stuff past the known exception of out private solar system. (and all the other options don't discover anything.)

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.