Which of the following is a key factor influencing a wine's body?

The choice that includes all factors influencing a wine's body is the most comprehensive answer. A wine’s body refers to its perceived weight and fullness on the palate, which can be influenced by several key elements.

Alcohol content plays a significant role in determining a wine's body. Higher alcohol levels generally contribute to a fuller, richer mouthfeel. Wines with higher alcohol content tend to feel more substantial and can leave a lasting impression.

Acidity is another crucial factor. Wines with higher acidity often feel lighter and crisper, which can create a different perception of body. Conversely, lower acidity can give a wine a rounder and fuller taste, enhancing the overall body.

Residual sugar also significantly impacts the body of a wine. Sweet wines, which have higher residual sugar, will generally feel fuller and more substantial in the mouth compared to dry wines, which tend to have less sugar and can feel lighter.

Each of these elements—alcohol, acidity, and residual sugar—contributes to the overall impression of body in a wine. Therefore, the choice that encompasses all three is correct, reflecting the multifaceted nature of a wine's body.