In a tension member, if one or more than one rivet hole are off the line, the failure of the member depends upon the pitch, gauge, and diameter of the rivet holes. This means that all of the options mentioned - pitch, gauge, and diameter of the rivet holes - are correct.

Let's understand why this is the case:

1. Pitch: The pitch refers to the distance between the centers of adjacent rivet holes along the length of the member. When a rivet hole is off the line, it affects the pitch. If the pitch is not maintained properly, it can lead to uneven distribution of load and stress concentrations. This can weaken the member and result in failure.

2. Gauge: The gauge refers to the distance between the centers of rivet holes in the transverse direction of the member. Similar to the pitch, if the gauge is not maintained properly due to off-line rivet holes, it can lead to uneven distribution of load and stress concentrations. This can also weaken the member and result in failure.

3. Diameter of the rivet holes: The diameter of the rivet holes is also important for the strength of the tension member. If the rivet holes are not drilled properly or if their diameter is not appropriate, it can affect the fit and strength of the rivets. This can lead to reduced load-carrying capacity and potential failure of the member.

All of these factors - pitch, gauge, and diameter of the rivet holes - are interrelated and contribute to the overall strength and integrity of the tension member. If any of them are compromised due to off-line rivet holes, it can significantly reduce the member's ability to withstand tension forces and result in failure.

Therefore, it is crucial to ensure that all rivet holes are drilled accurately and are in line to maintain the required pitch, gauge, and diameter for a tension member to perform effectively and safely.