Which technique uses sound waves to measure the depth of the ocean floor?

Echosounders

This method of seafloor mapping is called echosounding. Echosounders can use different frequencies of sound to find out different things about the ocean.

the correct answer is "c": the pillars proclaimed his regret at the bloodshed at the battle of kalinga and his conversion to buddhism.

the kalinga war is considered as one of the largest battles in the history of india. it was fought between the between the maurya empire, which ruled the lands of what is now known as india at the time, and the independent feudal kingdom of kalinga.

the army of maurya empire, led by its king ashoka, fought a prolonged war against kalinga. the war ended around 262 bce with the victory of the maurya empire. it is believed that ashoka, after having witnessed the loss of many lives during this war, felt deep responsibility and eventually converted into buddhism.