What does the outward taper of a tapered pilsner glass support?

The outward taper of a tapered pilsner glass is specifically designed to support the head of the beer. A well-formed head is an essential aspect of serving pilsner, as it contributes to the overall sensory experience, enhancing both aroma and visual appeal. The taper helps to hold the foam in place, allowing it to maintain its structure and persist for a longer period. This design effectively traps aromatic compounds within the glass, focusing them toward the drinker's nose as they take a sip, thereby boosting the perception of aroma.

While other elements like aroma concentration and temperature retention are important for the overall beer experience, the primary function of the tapered shape in this context is to enhance the presence and longevity of the beer's head, making option C the most suitable choice.