Which of the statements are examples of signaling? Choose all that apply. There is more than one correct answer,

Jo decides to go to graduate school so her future employer will know that she is smart and a hard worker,

Fred's Used Cars offers a warranty on every car sold.

Tommy's Tea Shop advertises by recording the testimonials of satisfied customers.

A name$-$brand bleach is priced $45\%$ higher per gallon than the generic alternative.

Haley uses her $4\mathrm{.}0$ grade point average to land a new job.