Ambiguous sentences

A sentence is said to be ambiguous if it has more than one meaning. Which of the following sentences are ambiguous?

(i) They are looking for teachers of Japanese, Portuguese and Spanish.
(ii) Flying planes are dangerous.
(iii) The old man and woman left the hotel.
(iv) The lady looked at the man with the binoculars.

Choose one answer
1) All of the above
2). (ii), (iii) and (iv)
3). (i), (ii) and (iii)
4)(i), (iii) and (iv)
i think the answer is 2 but i am not sure