I'd say the correct answer is D - mythological. Because Neptune is the god of freshwater and the sea in Roman mythology, and he has a counterpart in Greek mythology - Poseidon.
"To try to write certain sentences is difficult"
The correct statements are 1, 2 and 3.
1) The sentence is correctly written. The pattern "to try to do something" is correct and can be used.
2) The sentence contains more than one infinitive. It contains two infinitive verbs. TO TRY and TO WRITE.
3) One infinitive is inside another infinitive phrase. "To try to write certain sentences" is an infinitive phrase, it functions as a noun because it is the subject of the sentences. So, the second TO INFINITIVE is inside the main infinitive phrase. (That is the reason why number 4 is not correct)
B. She constantly scowls, but is really a nice, caring person.
This is correct. You can notice this occurrence on acronyms such as NASA, CIA, FBI, etc...
