I think the answer is the density of the soil.
Hope this helps
If not, am sorry
The answer will be the 4th option
A tectonic hazard would be something that isn't expected but only lasts so long.
Example: an earthquake or tsunami
The best example is an earthquake
Immediate responses would be to take shelter under a sturdy building or get to high grounds where nothing can fall on you.
The number of deaths could be reduced by having regular safety checks of buildings and if you know you are near tectonic plate shifting then the building should be built with study material.
Lava and other materials that are launched from a volcano into the air are referred to as tephra. The correct option among all the options given in the question is option "A".Tephra is actually the material that is ejected by an active
volcano irrespective of the type of the material, fragment size or emplacement
mechanism. The airborne substances of the volcanoes are known by the name
pyroclasts. The pyroclasts remain as tephra unless they become hot enough to
fuse together.
