Through reason as well as looking at the diagram, the given statements that bust be true are:
A. AD<DB because D is less than half way across line AB, and is closer to A than B.
B. AD<CB because CB definitely accounts for half of the line, whereas AD accounts for less than half of line AB.
D. AD+DC=CB because AD+DC= AC, and we know that both AC and CB are half of line AB.