Answer:
it is c because trouble cannot stare it has no eyes
The narrator meets the Medical Man at the Linnaean Society in the city. The Medical Man thinks the Time Machine thing was a trick, but he can't figure out how the Time Traveller did it. The narrator goes back the following week for the Time Traveller's weekly dinner party.
The sky describes the feeling of freedom
The answer is c. He was tired and it was late; it had been a long day. The semi-colon helps distinguish the two separate parts. The part where it says "it had been a long day" doesn't make sense if added by a comma.