If numbers x, y, z are all less than 40, how many of them are positive?
I. x + y = 46
II. x + y + z = 80

A

if the statement I alone can give the answer to the question.

B

if the statement II alone can give the answer to the question.

C

if the statements I and II together are necessary to give the answer to the question.

D

if the statements I and II both are not sufficient to answer the question and additional information is necessary