What is the difference between a root gap and a root opening, and how do these affect GTAW?

What is the difference between a root gap and a root opening, and how do these affect GTAW?

• A. Root opening is defined as the air gap at the root; Root gap is the distance between the base-metal faces.
• B. Root gap is the actual air gap at the root.
• C. Root gap refers to electrode gap; root opening refers to arc length.
• D. Root gap is the distance between the base-metal faces; root opening is the actual air gap at the root.

Answer: (D)