Answer:
A) sea level drops; land subsides
Explanation:
The sea is the final destination of all streams on land. All streams empty into seas which are the basins that collects all terrestrial materials.
The base level is the lowest level to which a river can erode its channel. The base level is greatly influenced by what happens to a sea.
When a river reaches its base level, erosion ceases. If a river is young and set above its base level, we see a rapid rate of erosion.
A sea, the final basin of depostion of rivers controls the base level to a very large extent. When there is a tectonic movement and a sea subsides. It becomes more deeper and lower. Sea level also falls and materials grades seaward. A river would cut rapidly along its channel and its bed to measure up to the level of the ocean.
Therefore, we see a very rapid rate of erosion of channels when sea level falls and the earth sags downward. This would lead to a lower base level.
When sea level rises and there is a tectonic uplift, rivers erode their channels less and begins to aggrade materials. The base level also rises.
This is wrong because it’s not the coordinates
Answer: 
Explanation:
The Tropic of Cancer is one of the parallels (imaginary line around the Earth parallel to the equator) located in the northern hemisphere (currently its latitude is 
).
It is called "Cancer" because a long time ago, when the summer solstice occurred in the northern hemisphere (on June 20th or 21st), the Sun was in the constellation Cancer (the crab).
Now, if we were just in the North Pole, Polaris would by exactly over our heads (
over the horizon), but as we go south and find the Tropic of Cancer parallel, Polaris altitude will be approximately at an angle of over the horizon.
Hence, the altitude of Polaris measured by an observer at the Tropic of Cancer is .
