Questions are based on the following passage．
Next month， New York students in grades three through eight will take the state"s standardized tests: three days of exams devoted to English Language Arts and Mathematics tests， except Art， Gym， Health， History and Science which are set up in the usual classes．These are often referred to as high- stakes tests because of the impact that the results can have on student promotion， teacher evaluation， and school funding——and the stakes of the tests in New York this year may be pushed higher still．
In his State of the State address， Governor Andrew Cuomo pledged to make education reform. a centerpiece （最重要的部分） of his agenda．"Everyone will tell you， nationwide， the key to education reform. is a teacher evaluation system，" the governor said．He noted that while only thirty-eight Percent of New York State high-school students are deemed to be "college ready"， according to their scores on standardized tests， 98．7 percent of teachers in New York"s schools are rated "effective"．" How can that be？The problem is clear and the solution is clear．We need real， accurate， fair teacher evaluations．"" But how teachers might best be evaluated remains a contested science．In New York City．a system which was adopted by Cuomo in 2013 is that students" results in state tests account for 20% of a teacher"s rating， but the teacher"s curriculum materials are also evaluated， as is his or her classroom practice， which is observed on multiple visits throughout the year by the school principal．Any teacher deemed ineffective for two continuous years may be fired．
Cuomo"s assertion is not universally shared．Those who have disagreed with it warned excessive reliance on test scores will cause teaching for tests rather than for learning．Others have said teachers may focus on improving their most able students at the expense of nurturing the capacities of the least able members．
In the light of the widespread doubt about over-reliance on test results and the widespread consensus about the harmful effects caused by teaching for tests， that test results are used to assess teachers" effectiveness seems a questionable calculation．It looks likely， though， that．should Cuomo"s proposal come into effect， test-prep season will start a lot earlier next year．for everyone．
Why are the standardized tests considered as tests with high risk？ 查看材料

A. Because the results can affect student promotion， teacher evaluation and school funding．
Because the results will determine whether the students will be able to graduate．
C. Because the exams will last for a really long time．
D. Because the exams are difficult and few students can pass them．