He major difficulty in designing line graphs (a)-lies in selecting the appropriate color to shade each line (b)-lies in properly choosing the spacing for each axis (c)-lies in making sure that more than three data lines are not separated by visible space (d)-lies in properly placing the independent variable and the dependent variable

d) lies in properly placing the independent variable and the dependent variable.

Explanation: Line graphs are the graph that display value of sometime in accordance with the time. The line has two axis names as x-axis on horizontal line and y-axis on vertical line. Independent variables are usually displayed on the x-axis and y-axis has the dependent variable.

The values are needed to be plotted carefully so that the graph obtained is correct. If the placement of independent and dependent value is incorrect, or on incorrect axis leads to incorrect design of graph.

answer:

in baseband transmission the whole bandwidth of the cable is utilized by a single signal. eg.Ethernet is using Basebands for LAN.

In the broadband transmission, multiple signals are sent on multiple frequencies simultaneously using a single channel. eg.Digital Subscriber Line (DSL)