sc og一道语法题 麻烦大神进来指点！！

ifcan1314

The first decision for most tenants living in a building  undergoing being converted to cooperative ownership is if to
sign a no-buy pledge with the other tenants.
1）undergoing 是修饰building，正确吗 ？（可以是修饰tenants，人发出undergo这个动作，哪种修饰正确 ？）
2）undergoing being converted  这里是两个动词连用 ？prep解答 undergoing已经表示了动作正在进行中，用being是多余的，我觉得这里是语法错误。  怎么理解  ？

A. being converted to cooperative ownership is if to sign
B. being converted to cooperative ownership is whether they should be signing
C. being converted to cooperative ownership is whether or not they sign
D. conversion to cooperative ownership is if to sign
E. conversion to cooperative ownership is whether to sign

喜皮

非大神，一点小小的理解，抛砖引玉哈
首先撇开修饰看句子的主体结构：the first decision for most tenants is if to sign...然后知道这里用whether比较好
然后再看modifier部分，undergoing应该是修饰building，因为noun modifier 越靠近修饰词越好，而且逻辑上也说得通【这个知识点可参考曼哈顿6th】
第二个问题，其实我觉得两个错因都可以解释的通…

蟹黄味蚕豆

第一个问题，undergoing只能修饰building。与其说是语法的就进修饰，不如说是句意思。tenant是人，人怎么可能经历被改造成集体所有呢？所以，探讨修饰人时，用什么形式，意义不大。
第二个问题 楼主说有语法错误是质疑prep的解答？还是认同prep的解答呢？