PART a If Cell Phone Companies Screen Text Messages, Then $\begin{array} { l } \text { \text { If } C \text { then } F \text {. }}\\ \text {C }\\ \hline\text { F}\\\end{array}$

PART A If cell phone companies screen text messages, then freedom of speech is threatened. Thus, freedom of speech is not threatened, because cell phone companies do not screen text messages.
Which of the following correctly expresses the form of this argument? a. $\begin{array} { l } \text { \text { If } C \text { then } F \text {. }}\\ \text {C }\\ \hline\text { F}\\\end{array}$$\quad$ b. $\begin{array} { l } \text { not F}\\ \text {not C }\\ \hline\text {\text { If } C \text { then } F \text {. } }\\\end{array}$$\quad$ c. $\begin{array} { l }\text { All C ate } F \text {. }\\ \text {C }\\ \hline\text {F }\\\end{array}$

d. $\begin{array} { l } \text {If \( \mathrm{C} \) then \( \mathrm{F} \). }\\ \text {Not C. }\\ \text {Not F. }\\\end{array}$$\quad$ e. $\begin{array} { l } \text {If \( \mathrm{C} \) then \( \mathrm{F} \). }\\ \text {Not F. }\\ \text { Not C.}\\\end{array}$ PART B
Which of the following substitutions proves the argument invalid?
A) C = Abraham Lincoln was assassinated, F = George Washington was assassinated.
B) C = Joe Smith was beheaded, F= Joe Smith is dead.
C) C = Abraham Lincoln was beheaded, F = Abraham Lincoln is dead.
D) C = Abraham Lincoln was assassinated, F = Abraham Lincoln is dead.
E) C = Abraham Lincoln was beheaded, F = Abraham Lincoln is not dead.