Look at the model of an arm that Ravi made. What does this model demonstrate? (i) Muscles in the arm work in pairs. (ii) The arm is made of bone and muscles. (iii) The arm can bend and straighten

• A.  Only (i) and (ii)
• B.                         Only (ii) and (iii)
• C.                         Only (i) and (iii)
• D.                         (i), (ii) and (iii)