A cliff is a rock exposure with a near vertical (or is vertical) facing. An escarpment is a long cliff, or steep slope. (causes faulting processes)
Mesosphere is the layer after stratosphere, which is after troposphere, as seen from Earth in the direction of Space.
It starts at 60 km and ends at 120 km, after which comes the termosphere.
So we're looking for a line that's closest to 100 km, and this is the shortest line, A.
United States Constitution was ratified in 1789, but had not much without a very considerable debate. During Constitutional Convention, delegates debated major issues such as the makeup of the legislature and the effect of slavery on representation.
