There needs to be a comma at A because it is an appositive phrase. Meaning he is describing someone or something and that is separate from the sentence its self
Core beliefs are those you hold most dear. There are usually started from things such as environment, family, and friends. I hope this helps :-)
Answer:
a series of recent post by astronauts.
Explanation:
this would be the most reliable source because it is first hand information, instead of people who havent visited space or traveled space.