Final answer:
Renaissance artists contributed to art evolution by diversifying subjects beyond religion, introducing realistic depiction via perspective, and anatomical accuracy, not directly promoting democratic values but emphasizing humanism.
Step-by-step explanation:
Renaissance Artists and Their Impact on Art
Renaissance artists significantly contributed to the evolution of art by freeing art from spiritual and religious concerns, bringing about a return to the realistic depiction of subjects, and exploring the structure and form of objects. Artists like Leonardo da Vinci, Michelangelo, and Donatello were at the forefront of this movement, driving the transformation of artistic expression;
Concerning (a), Renaissance artists after the Protestant Reformation began to paint not only religious themes but also private portraits, thus diversifying art beyond ecclesiastical subjects. Regarding (b), the invention of linear perspective by artists such as Filippo Brunelleschi allowed for a more realistic and three-dimensional representation of space. With (c), artists' interest in human anatomy led them to conduct dissections, enriching their understanding of the human form which they then accurately represented in their work. Finally, in relation to (d) while the direct promotion of the values of a rational and democratic society wasn't a primary characteristic of Renaissance art, the focus on humanism and individualism can be seen as indirectly supporting these ideas.
The Early Renaissance marked the beginning of these changes as artists like Cimabue and Giotto moved away from the Byzantine style of religious paintings. Further advancements in techniques and broader thematic choices were evident in the works of Andrea Mantegna and Paolo Uccello, who mastered the use of one-point perspective. All these developments contributed to a more nuanced representation of the human experience, which often reflected the societal changes of the time.