"When the debate is lost, slander becomes the tool of the loser(s)" refers to certain people's tendency to turn the biterness and humiliation of losing an argument into personal attacks against the debate opponent and their image.
To <em>slander</em> means to defame, to say false things about someone in an attempt to damage their reputation.
This statement is often attibuted to Greek philosopher Socrates, but there isn't any evidence supporting the fact that he originated the phrase, so it would be best to avoid quoting Socrates in this case, especially in school assignments.
Both sentences A and B are capitalized correctly:
Only one solution is possible: We must cut our expenses.
Only one solution is possible: we must cut our expenses.
The first word of both sentences (only) must always be capitalized since it is placed at the beginning.
On the other hand, if the sentence following the colon is dependent (it is incomplete), its first word should not be capitalized. For example:
"I have to buy three things: apples, oranges and bananas."
Regarding capitalization in independent clauses following a colon (such as the one given in the example), it is subject to the citation style the writer is following (APA, MLA, etc). While some styles recommend capitalization of the first word of the sentence, some others do not.
