Answer:
D. harmony and proportion.
Step-by-step explanation:
Principles of designs can be defined as concepts which are typically used for organizing or arranging the structural
elements of a design. Thus, the ways in which these principles are applied generally affects the message of a piece of work.
Renaissance architects designed structures that were considered beautiful because of their harmony and proportion.
Basically, their designs were typically created with a high degree of uniformity and balance in the components.