Final answer:
The correct answer is d) Straightening cream, which is designed to help straighten damp wavy or curling hair when applied before blow drying.
Step-by-step explanation:
A styling aid that is applied to damp wavy or curling hair to create a straight look when blown dry from the given options would be d) Straightening cream. While mousse can add volume, gel can define curls, and serum can smooth frizz, it is the straightening cream that is specifically formulated to facilitate the straightening process during heat styling. This type of product often contains conditioning agents and polymers that protect the hair from heat damage and help achieve a sleek, straight style as hair is dried with a blow-dryer. Hair spray is used to hold a style in place after the hair is already dried and styled, and perms are techniques involving either thermal or chemical means to curl or straighten the hair.