Final answer:
The correct combination of fittings for making an offset in a vertical pipe is Elbow and Tee, which are used to change the direction of the pipe and provide a branch line respectively.
Step-by-step explanation:
The combination of fittings that may be used to make an offset and is considered a vertical pipe are Elbow and Tee. These fittings allow pipes to change direction or to branch off.
An elbow fitting is used to change the direction of a pipe line, and when a vertical offset is needed, two elbows can be used to achieve this. A tee fitting is used to either combine or split flow in a piping system, and when it is a part of a vertical pipe installation, it can provide a branch line.