Its b.
A is wrong because the parenthesis are not needed, C needs comma, and d uses too many commas.
i would go with semicolon
Kennedy's claim is that sending a rocket into space in such a short amount of time is a risky, bold thing to do.
He is victorious but spares his opponent's life. His men are loyal to him, and he is kind to them
Slogan is pretty much like your ad or logo. It's a type of technique you'd use to get people to believe your product actually does what you say it does. Your slogan is also how people make ads rhyme and make it seem so good.
I hope that this helps with whatever you needed to know about a slogan. :)
