Which of the following burns affects the top layer of skin only and does not cause scarring?

Partial thickness burns, or second-degree burns, extend deeper into the dermis and can lead to blisters and significant pain. These burns often result in scarring due to the involvement of deeper skin layers, which contradicts the question's requirement for a burn that does not scar.

Full thickness burns, or third-degree burns, affect all layers of the skin, including the subcutaneous tissue. They are severe and typically require medical intervention for healing, often resulting in noticeable scarring and significant damage to the skin structure.

Deep burns usually refer to fourth-degree burns, which penetrate through the skin into underlying tissues, including muscles and bones. These burns are critical and lead to extensive damage and scarring, making them clearly unsuitable as an answer to the question.

This option is a repetition of "full thickness" and does not alter the explanation. Full thickness burns involve complete destruction of skin layers and result in severe scarring, thus failing to meet the criteria specified in the question.