Which sentence does not contain any errors in comma usage?
a. in vienna musicians first played the harpsichord, but then someone invented the piano.
b. in vienna musicians first played the harpsichord, but, then someone invented the piano.
c. in vienna musicians first played the harpsichord but, then someone invented the piano.
d. in vienna musicians first played the harpsichord but then someone invented the piano.

Read the paragraph from a student's literary essay comparing two different works (1) sandra cisneros's "mericans" is about a young american girl of mexican descent who is struggling to find her own cultural identity (2) cisneros illustrates this through a number of images and ideas. (3) for example, the speaker, micaela, calls her grandmother "awful," and seems to resent the woman's strict views and religious ideals. (4) the speaker also mentions how she and her brother emulate characters from popular american television programs when they play make-believe. (5) lastly, she describes physically standing outside her family's church, an act that symbolizes the fact that she feels like an outsider to mexican culture. (6) although micaela is of mexican descent, she seems to feel a stronger connection to the united states. this paragraph supports the idea that micaela wishes her heritage was different because she has difficulty relating to her grandmother. wants to find her own unique identity that is separate from her brother and her grandmother will never accept her mexican roots because of her feelings toward her grandmother identifies with her mexican heritage in a different way than her grandmother mark this and return save and exit next submit