This question seems to be incomplete. However, there´s enough information to find the right answer.
Answer: Dorian was the son of Lady Margaret Devereux. His mother was a glamorous high-class woman that had gotten married to Dorian´s father against her own father´s wishes. Lord Kelso, her father, disliked that she had married below her class, so he hired someone to provoke Dorian's father into a duel that has him killed. Margaret dies soon after she goes back to live with Kelso and Dorian ends up being raised by his grandfather, despite their mutual dislike for each other.
Explanation:
Dorian is the main character from Oscar Wilde´s "The Picture of Dorian Gray" (1890).
Sharing a difficult experience can strengthen a friendship.
The correct answer is - When studying mythology, I learned about several gods and goddesses: Zeus, Apollo, Aphrodite, Hermes, and Hercules.
This is the only sentence which is punctuated correctly because the first part (before the list) ends abruptly; it is obvious that something needs to be placed there. In this case, that is a colon.
The other sentences have leading words (particularly, such as, were) that don't require a colon after them.
