Which of the following choices is primarily involved in developing a cohesive look for an event?

Developing themes is primarily involved in creating a cohesive look for an event because a theme serves as the foundation for the event's design and overall aesthetic. It integrates all the elements of the event, including decor, color schemes, signage, and even the attire of staff or participants. A well-defined theme ensures that everything aligns visually and conceptually, resulting in a unified experience for attendees.

While aspects like choosing menus, managing response cards, and coordinating transportation are essential to the event’s overall functionality and logistics, they do not directly contribute to establishing the visual and experiential quality that a theme provides. A theme encapsulates the spirit and message of the event, making it a crucial element for creating that cohesive look.