Committee X and committee Y, which have no common members, will combine to form Committee Z. Does Committee X have more members than Committee Y ？（）
(1)The average (arithmetic mean) age of the members of Committee X is 25.7 years and the average age of the members of Committee Y is 29.3 years.
(2)The average (arithmetic mean) age of the members of Committee Z will be 26.6 years.
A.条件（1）充分，但条件（2）不充分.
B.条件（2）充分，但条件（1）不充分.
C.条件（1）和（2）单独都不充分，但条件（1）和条件（2）联合起来充分.
D.条件（1）充分，条件（2）也充分.
E.条件（1）和条件（2）单独都不充分，条件（1）和条件（2）联合起来也不充分.
