What did the argument between king henry and pope gregory VII demonstrate

The conflict between Henry IV and Gregory VII concerned the question of who got to appoint local church officials. Henry believed that, as king, he had the right to appoint the bishops of the German church. This was known as lay investiture.

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.