The symbol below shows the use of what type of weld?

The image displays a welding symbol. Let's break down its components:

1. V-shape symbol on the arrow side (above the reference line): This symbol indicates a Single-V-groove weld. The arrow side refers to the side of the joint to which the arrow points.
2. Semicircle symbol on the other side (below the reference line): This symbol represents either a Back weld or a Backing weld. In welding standards like AWS A2.4, the symbol for both a back weld and a backing weld is the same semicircle.
   • A backing weld is typically applied to the root side of a groove weld to provide support for the root pass.
   • A back weld is typically applied to the back side of a single-groove weld after the groove weld has been completed, often for reinforcement or to ensure full penetration.

The question asks what type of weld the symbol shows. The symbol clearly indicates both a single-V-groove weld and a weld on the opposite side. Given the options, we need to choose between "Back weld" and "Backing weld" for the semicircle symbol. While the symbol itself doesn't distinguish between the two, "backing weld" is a very common term for the weld applied to support the root of a groove weld.

Therefore, the symbol represents a combination of a single-V-groove weld and a backing weld.

• A. Back weld: Refers to the semicircle symbol.
• B. Backing weld: Refers to the semicircle symbol.
• C. Single-V-groove weld: Refers to the V-shape symbol.
• D. A and C above: Implies a Back weld and a Single-V-groove weld.
• E. B and C above: Implies a Backing weld and a Single-V-groove weld.

Considering the common interpretation of welding symbols, option E provides the most comprehensive and commonly accepted description of the features shown.

The final answer is $\boxed{\text{E. B and C above}}$