Hello anyone from USA here?​

Aids is growing fastest in the poorest countries of africa. these nations don’t have enough doctors, medical labs, or money for medicine. a recent study showed that only a small percentage of hiv-infected children in africa are getting any medical treatment at all. what central idea is emphasized in both sources? the hiv/aids epidemic in africa is serious. the hiv/aids epidemic in south africa is serious. the hiv/aids epidemic among african children is serious. the hiv/aids epidemic among south african children is serious

[1] when the twins grew up, they continued to fight. [2] one day they decided to hold a contest to determine who was stronger. [3] though they tried to defeat each other in many different ways, neither one could win. [4] on the last day, they fought with weapons. [5] using a deer antler, the right-handed twin overpowered his brother, and he threw him off the edge of the earth. [6] today, the right-handed twin lives in the sky-world, and the left-handed twin lives in the dark underworld. [7] they rule the earthly world of men together.

What makes the following sentence unclear? i had hoped to finish the race and win a medal, but i didn’t. a) nothing. the sentence contains no errors. b) there is no independent clause so the sentence is incomplete. c) it’s a simple sentence and doesn’t need a comma. d) there are two possible meanings to the sentence.