GROUP of words is 'Audible'. Let's look at the meaning and examples of the words given in the options: LegibleLegible writing or print can be read easilyHer handwriting is barely legible.Ediblesuitable or safe for eatingOnly the leaves of the plant are edible.Tangiblereal and not IMAGINARY; able to be shown, TOUCHED, or experiencedWe need tangible evidence if we're going to take legal action.Audibleable to be heardThe lecturer spoke so quietly that he was scarcely audible at the back of the hall.Hence, by READING the above explanation we find that the correct answer is OPTION 4.