It shifted like, most people who liked art and actually cared about it would go to art shows and spend tons of money on art. So, basically if you liked art you were in a small group of people in this time period. There were only so many people who actually liked art.
1. Books 2. Enclyclopedias 3. Interviews
A commemorative speech has to do with celebrating something or someone. If you want to pay tribute to someone (and there isn't a specific topic you have to talk about), you should talk about someone important to you, someone whom you love and who inspires you - it could be a family member or a friend, or someone you look up to.
D, or the 4th one. It combines the sentences effectively, without overusing words.