a. The subject's clothes that he is rich and important. He is wearing velvet clothes, which represented wealth during the Renaissance.
b. The background may be the land he owns or has power over. It is important because it shows the viewer how important/rich he is.
c. The artist wants the viewer to think that he subject is an important person because of the background he includes and the clothes the subject is wearing.
d. The subject's name is Carl. His family is very wealthy and owns a lot of land. He is kind and smart. He enjoys reading, writing, painting, and various other activities. He cares about his family's reputation and his town.