The answer is B because "I have visited many cities including the following" indicates that there is going to be a list of cities. A colon is used to introduce a series of items or to separate two independent clauses; however the second sentence has to add on to the first.
The last one is the correct answer.
It is "It's going to be a long wait," the nurse confided.
When someone is speaking, there needs to be quotation marks. Also, <em>It's</em> needs an apostrophe because that makes it stand for "It is"
So the last answer is the right one.
D.the newscasters on channel 20 seems very friendly