大全808 时态问题

六月未名

808.    The proposed health care bill would increase government regulation of health insurance, establish standards that would guarantee wider access to people with past health problems and to workers changing jobs who otherwise could be uncovered for months.
(A) establish standards that would guarantee wider access to people with past health problems and to workers changing jobs who
(B) establishing standards that would guarantee wider access to people with past health problems and to workers who are changing jobs and
(C) to establish standards that would guarantee wider access to people with past health problems and to workers who change jobs that
(D) for establishing standards that would guarantee wider access for people with past health problems and workers changing jobs who
(E) for the establishment of standards that would guarantee wider access for people with past health problems and workers who are changing jobs that

这道题我知道选B了，也知道其他几个为什么错，就是想再讨论一下关于B选项中"are chaning jobs"的时态问题，这里用一般现在进行时没问题吗？整篇文章不是过去时的吗？怎么解释？