Final answer:
4. A strike-slip fault typically generates the smallest fault scarp due to its horizontal motion, whereas normal, reverse, and thrust faults involve vertical displacement and can produce more pronounced fault scarps.
Step-by-step explanation:
The kind of fault that would generally generate the smallest fault scarp is Option 4: Strike-slip fault. Fault scarps are created when there is vertical movement along a fault, causing one side to be displaced up or down relative to the other. In contrast, strike-slip faults involve horizontal motion, where the blocks move laterally past one another.
This type of motion does not typically result in a significant vertical displacement, therefore producing little to no fault scarp.
Other types of faults like normal faults, reverse faults, and thrust faults often involve vertical displacement known as dip-slip motion. Normal faults occur with extension of the Earth's crust where the hanging wall moves down. Reverse and thrust faults are the result of compression and shortening, with the hanging wall moving upwards, and can create notable fault scarps.