the answer is D. Some of the world’s highest waterfalls can be found in three countries: Venezuela, South Africa, and Peru.
a colon in a sentence means the auther can end the sentence with a period if he wanted and the sentence would still be correct.
in this case the sentence could be, "Some of the world’s highest waterfalls can be found in three countries."
this still looks and sounds correct and is a fully functioning sentence.
Today's music tracks are meaningful not educational. Reason why, you could listen to it all day and it has a meaning behind those songs if you really dig into it.
Your teacher will for a fact i know that so dont use it twice