PART a All Corporate Mergers Are Either Success Stories or Fiascos

PART A All corporate mergers are either success stories or fiascos. Hence, some corporate mergers are fiascos.
Which of the following correctly expresses the form of this argument?
A) All C are S.
B) All CM are either S or F.
Some C are F.
Some C are F.
C) Some C are F.
D) All C are either S or F.
All C are either S or F.
Some C are F.
E) If C then either S or F.
If C then F.
PART B
Which of the following substitutions proves the argument invalid?

A) $\mathrm { C } = \text { mammals. } \mathrm { F } = \text { dogs. } \mathrm { S } = \text { cats. }$
B) $\mathrm { C } = \operatorname { dogs } , \mathrm { S } = \text { mammals, } \mathrm { F } = \mathrm { fish } .$
C) $\mathrm { C } = \text { animals, } \mathrm { S } = \text { fish, } \mathrm { F } = \text { mammals. }$
D) $\mathrm { C } =$ Leonardo DiCaprio is a man, $\mathrm { S } =$ Leonardo DiCaprio is a human, $\mathrm { F } =$ Leonardo DiCaprio is a woman.
E) $\mathrm { C } = \text { cats, } \mathrm { S } = \text { mammals, } \mathrm { F } = \text { animals. }$