PART a If the Economy Crashes, Then Stock Prices Fall

PART A If the economy crashes, then stock prices fall, because if stock prices fall, then pension funds shrink, and if the economy crashes then pension funds shrink.
The form of this argument is: a. $\begin{array} { l } \text {\(\text { If E then } S \text {. }\) }\\ \text {\(\text { If } E \text { then } P \text {. }\) }\\ \hline\text { \(\text { If } \mathrm{S} \text { then } \mathrm{P} \text {. }\)}\\\end{array}$$\quad$ b. $\begin{array} { l } \text {If \( E \) then \( S \). }\\ \text {\(\text { If } \mathrm{S} \text { then } \mathrm{P} \text {. }\) }\\ \hline\text { \(\text { If } E \text { thet } P \text {. }\)}\\\end{array}$$\quad$ c. $\begin{array} { l } \text {If \( S \) then \( P \). }\\ \text {\(\text { If } E \text { then } P \text {. }\) }\\ \hline\text {\(\text { If } E \text { then } S \text {. }\) }\\\end{array}$

d. $\begin{array} { l } \text {All \( \mathrm{S} \) are \( \mathrm{P} \). }\\ \text {All E ate P. }\\ \text { All \( \mathrm{E} \) ate \( \mathrm{S} \).}\\\end{array}$$\quad$ e. $\begin{array} { l } \text {If \( \mathrm{S} \) then \( \mathrm{P} \). }\\ \text {If \( E \) then \( S \). }\\ \text { If \( E \) then \( P \).}\\\end{array}$ PART B
Which of the following substitutions proves the argument invalid?
A) S = Jessica Biel is a man, P = Jessica Biel is a human, E = Jessica Biel is a woman.
B) S = cats, P = animals, E = dogs.
C) S = Jessica Biel is a woman, P = Jessica Biel is a human, E = Jessica Biel is an actress.
D) S = Matt Damon is an actor, P = Matt Damon is a lawyer, E = Matt Damon is a professional.
E) S = Susan is rich, P = Susan is famous, E = Susan is happy.