What do researchers use to look at Earth’s innards? pls help meh :(((

Researchers such as Barbara Romanowicz at the University of California, Berkeley are using seismic (earthquake) waves to scan our planet's innards, much like doctors use ultrasound to peer inside patients.

Explanation:

One ingenious way scientists learn about Earth's interior is by looking at how energy travels from the point of an earthquake. These are seismic waves (figure 1). Seismic waves travel outward in all directions from where the ground breaks at an earthquake. These waves are picked up by seismographs around the world.

the answer is c my brotha. c.   formed an alliance with the soviet union.