[求助]GWD CR 问题，请教NN！

1. The current economic downturn has significantly reduced advertising income both for business journals as well as general consumer magazines, especially if focusing on technology.

B. has significantly reduced advertising income both for business journals and for general consumer magazines, especially those focusing

C. significantly reduced advertising income for both business journals and for general consumer magazines, especially when focused

答案说：“
        B is the best，both for ...and for平行。
            选项用的是现在完成时态，在没有明确的理由的时候，一般不要改变时态。Especially those focusing是本题很关键的一点。”请问这里those 不存在着指代不清的问题么（是business journals 还是magazines 抑或两者的总体）？
                

2

．Emily Dickinson’s letters to Susan Huntington Dickinson were written over a period beginning a few years before Susan’s marriage to Emily’s brother and ending shortly before Emily’s death in 1886, outnumbering her letters to anyone else.

1. Dickinson were written over a period beginning a few years before Susan’s marriage to Emily’s brother and ending shortly before Emily’s death in 1886, outnumbering

2. Dickinson, which were written over a period beginning a few years before Susan’s marriage to Emily’s brother and ending shortly before Emily’s death in 1886, outnumber

答案：B。  但是请问：
            请问A选项语法上有错误么？
            后面的”outnumbering … 是否可以看作是同位语修饰前面的letters?