请教：GWD7 Q23

panpanchen

搜过版面了，找到了有同学说是OG10里的题，可是我没有OG10；也看到斑竹给的链接，奈何号码对不上。。。。找不到啊

哪位好心的大侠给我解释这个图怎么看啊，谢谢啦！

Q23:

+    x    y    z    
d            m    
e        n        
f                
                


The figure above shows two entries, indicated by m and n, in an addition table.  What is the value of n + m?
(1)      d + y = -3
(2)      e + z = 12
    
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.