D. Soil is composed of weathered parent material where as crushed rock is not.
Answer: 
Explanation:
The angular diameter
of a spherical object is given by the following formula:

Where:
is the actual diameter
is the distance to the spherical object
Hence:

This is the angular diameter
I would say that the answer is C
Answer: A) Current
Current is the flow of electrons. The more electrons that flow, then the higher the amperage which measures this flow. If the current is high enough, then the electrical shock may cause damage of some kind.
"Amperage" is abbreviated as "Amp". You may see something like "milliamp" when it comes to measuring this amperage.