Answer:
B. The presence of an earthquake belt.
Explanation:
A rift valley only happens when the plates are diverging. A trench represents plates converging. And the presence of active volcanoes is only on converging and some diverging boundaries (hence there is no volcanoes in California). An earthquake is present in all plate boundaries.
<span>decreasing a telescopes eyepiece focal length will </span>increase magnification
The correct answer is - C. The river carried enormous amounts of silt.
The Yellow River, got this nickname because it is yellowish from the enormous amounts of silt it carries. When there were heavy rains, or the snow was melting, the river got more water, but also more silt, so the silt was partially blocking the free movement of all of the water, so it was flooding the surrounding are. In one way, the floods were terrible because they were destroying pretty much everything on their way, but on the other side, were living huge amounts of deposits that were fertilizing the soil for the agriculture.
I'm assuming you mean topographic maps, in that case C. Elevation