Final answer:
The product known for creating a sleek, smooth finish is the smoothing serum, which manages frizz and imparts a glossy look. It differs from hair spray, which holds a hairstyle in place but can leave a 'crunchy' texture.
Step-by-step explanation:
The hairstyling product that creates sleek, smooth finishes is C) Smoothing serum. Unlike texturizing spray, which adds texture and volume, or curl-enhancing gel designed to define curls, a smoothing serum is specifically formulated to control frizz and provide a glossy, sleek look. Its silicone-based ingredients coat the hair strand, leaving it silky and manageable. Smoothing serums are ideal for achieving a polished, straight hairstyle without the stiffness that hair spray can sometimes leave behind. Hair spray, in contrast, is more about securing a style in place and can give hair a 'crunchy' texture if not brushed out. It's essential to choose the right product for the desired outcome when styling hair.