PART a Some Cashmere Sweaters Are Fashionable Garments, So Some

PART A Some cashmere sweaters are fashionable garments, so some cashmere sweaters are not suede jackets, for some suede jackets are not fashionable garments.
Which of the following correctly expresses the form of this argument? a. $\begin{array} { l } \text {Some C are \( F \). }\\ \text { Some C are not \( \mathrm{S} \).}\\ \hline\text {Some \( S \) are not \( F \). }\\\end{array}$$\quad$ b. $\begin{array} { l } \text { Some \( S \) are not \( F \).}\\ \text {Some C are \( \mathrm{F} \). }\\ \hline\text { Some C are not \( \mathrm{S} \).}\\\end{array}$$\quad$ a. $\begin{array} { l } \text {Some \( \mathrm{S} \) are not \( \mathrm{F} \). }\\ \text {Some C arenot \( \mathrm{S} \). }\\ \hline\text { Some C are F.}\\\end{array}$

d. $\begin{array} { l } \text {Some F are not S. }\\ \text {Some \( \mathrm{F} \) are \( \mathrm{C} \). }\\ \text {Some \( S \) are not C. }\\\end{array}$$\quad$ e. $\begin{array} { l } \text {Some C are F. }\\ \text {Some \( \mathrm{F} \) are not \( \mathrm{S} \). }\\ \text {Some \( \mathrm{C} \) are not \( \mathrm{S} \). }\\\end{array}$$\quad$ PART B
Which of the following substitutions proves the argument invalid?
A) C = animals, F = cats, S = mammals.
B) C = dogs, F = animals, S = mammals.
C) C = dogs, F = mammals, S = fish.
D) C= mammals, F = animals, S = dogs.
E) C = cats, F = mammals, S = animals.