Researchers Manipulated the Tail Length in Male Widowbirds and Compared

Researchers manipulated the tail length in male widowbirds and compared female preferences for males with different tail lengths.Do the results illustrated in the figure below show that male tail length is an honest signal of male quality?

A) Yes, otherwise females would not prefer males with longer tails.
B) Yes, the longer the tail the more energy males need to spend on growing it.
C) No, just putting a longer tail on a male does not increase its quality.
D) No, this study did not test whether birds with naturally long tails were of higher quality than birds with naturally short tails.