6) Which of the following expressions is equivalent to the statement "Among all teachers, only those with a wealthy spouse own a luxury car"?

(A) If a person owns a luxury car, then they are a teacher or have a wealthy spouse.

(B) If a person is a teacher and has a wealthy spouse, then they own a luxury car.

(C) If a person is a teacher and owns a luxury car, then they have a wealthy spouse.

(D) If a person owns a luxury car, then they are a teacher and have a wealthy spouse.

(E) If a person has a wealthy spouse, then they are a teacher and own a luxury car.
6) The answer is (C). If $I(x), C R(x), A L(x)$ are the predicates " $x$ is a teacher", " $x$ has a wealthy spouse" and " $x$ has a luxury car", the assertion in the text becomes

$$
\forall x(I(x) \Longrightarrow(A L(x) \Longrightarrow C R(x)))
$$

which is obviously equivalent to

$$
\forall x(I(x) \& A L(x) \Longrightarrow C R(x)),
$$

which formalizes assertion (C).

On the other hand, it is clear that the assertion in the text does not impose on anyone to own a luxury car (as (B) and (E) do), nor does it impose on luxury car owners to be teachers (as (D) does), nor to have a wealthy spouse if they are not teachers (as (A) does).