Which of the following is so intimate it's often compared to a conversation among friends?
a. a concerto
b. a minuet
c. a string quartet
d. a social song

I would say a string quartet. A string quartet is only 4 instruments in total. Four instruments is typically too small for an orchestra, which is probably why the comparison is made.

Photography has changed its subject matter quite a lot over the past few years. in the 1800's, it was considered normal for families to have  post mortem photos of their loved ones, and now that would be completely unacceptable. i think that photographers have always pushed boundaries and have been eager to capture everything, it is just society that changes their boundaries.