Which one of the following statements is correct? (i) Loudness of sound is directly proportional to the square of amplitude vibrations. (ii) Sound can travel through vacuum. (iii) Speed of sound is maximum in solids. (iv) The outer part of ear is called ear canal.

• A. (i) and (ii)                      
• B. (ii) and (iii)
• C. (i) and (iii)         
• D. (i) and (iv)
• E. None of these