Question

the information i found has really helped me educate others in the ways__companies promote their

promote their products Athat Bwhere C where D what为什么选A不选C

Answer 1

way 是先行词时，关系词如果在定语从句中作方式状语可以有三种选择：
1. 省去关系词（最常用）
2. that
3. in which
所以你这里选A 。
where 是表地点的， 这里是方式

请及时采纳，不懂继续问
(*^__^*) 祝学习进步! 谢谢！

Answer 2

in the ways后面是关系代词that引导的关系从句，即定语从句。先行词是ways时，关系代词只能是that，that可以省略。