Which of the Following Sentences Is an Example of Ambiguity

Which of the following sentences is an example of ambiguity?

A) It is the consensus of opinion of our Human Resources Committee that work stoppages would decrease considerably and substantially if the equipment were kept in constant and complete repair.
B) The fact that you were provoked perhaps mitigates but certainly does not justify your action in attacking your companion.
C) Abraham Lincoln wrote the Gettysburg Address while travelling from Washington to Gettysburg on the back of an envelope.
D) Jacaranda and fig trees were planted alternately along the footpath.
E) The tendency to make social contacts is a constant factor in the sphere of human relationships.