Question

which of the following is used to determine the correct length of a pipe?
a. center point
b. middle
c. centerline
d. center

Explanation:

In pipe fitting and engineering, the centerline (an imaginary line running through the center of the pipe along its length) is used to measure the correct length of a pipe, as it accounts for the pipe's internal and external dimensions uniformly. Other options like center point (a single point), middle (a general term), or center (ambiguous) do not specifically refer to the linear reference needed for length measurement.

Answer:

C. Centerline