Answer to Question 1
A carbon star is a very old low-mass star, after it has passed through the red giant phase. Earth may survive the red giant phase of the Sun, as planets in similar systems have, but. the cool red radiation may make processes such as photosynthesis difficult. Maybe an advanced civilization could have developed around this star, but it would have had to make special arrangements to survive the red giant phase of its mother star.
Answer to Question 2
C