Slave Traders showed tremendous cruelty to their captives. Why would slave traders be hesitant to kill slaves?

Slaves were property

Explanation:

Slaves were essentially property, worth money and were used for extremely cheap labor. Killing the slave would essentially be purposely crashing your car. That is why slavers practiced cruel punishments such as beatings to discipline disobedient slaves.

the graph shows the spread of railways in the 1800s.

based on the graph, the conclusion that can be drawn about germany is answer d)   by 1880, germany had more rail lines than great britain and russia.