Is $$x = 0$$?
I.The arithmetic mean of x, y, z, t is 6.
II.The arithmetic mean of x, y, z, t is 8.

A

if the statements I alone is sufficient to answer the question.

B

if the statements II alone is sufficient to answer the question.

C

if the statements I and II together are sufficient to answer the question but neither statement alone is sufficient.

D

if both the statements I and II together are not sufficient to an answer the question and additional data is required.