GMAT CAT -5 SC doubt Berlin wall

[mehtamaulikd]

Since 1989, after the Berlin Wall had been demolished, one of the most problematic ethnic groups in the reunified Germany, in cultural and economic assimilation terms, were the former East Germans, who have had to acclimate to an entirely different political system.
A. after the Berlin Wall had been demolished, one of the most problematic ethnic groups in the reunified German, in cultural and economic assimilation terms, were the former East Germans
B. after the Berlin Wall was demolished, one of the most problematic ethnic groups in the reunified Germany, in cultural terms as well as those of economic assimilation, were the former East Germans
C. when the Berlin Wall was demolished, one of the reunified Germany's most problematic ethnic groups, in terms of cultural and economic assimilation, was the former East Germans
D. when the Berlin Wall was demolished, one of the most problematic ethnic groups in the reunified Germany, in terms of cultural and economic assimilation, has been the former East Germans
E. after the Berlin Wall had been demolished, one of the most problematic ethnic groups in the reunified Germany, in both terms of cultural and economic assimilation, have been the former East Germans

Doubt:- The correct answer here is D. But how can the same group be referred with a has in the underlined and have in the not underlined section ?
Please explain the reasoning for each and every answer choice. I choose A...

[girish_ns]

Hi Maulik,

In the underlined portion, the "has been" refers to "one" of the problematic ethnic groups. Since this verb refers to a collective noun, "one" group, it has to be singular - "has been"

In the non-underlined portion, the verb "have had" refers to the East Germans, which is a plural subject. As per the modifier rule, any wh- word placed after the comma should refer to the noun immediately preceeding the comma, this time the "East Germans"

Hope this helps.

[jnelson0612]

Good work girish.

[saxenankit]

Good work girish.

Dear Nelson,

Can you please through some light on the usage of "after" and "when", here

[tim]

1989 was WHEN the Berlin wall was demolished, not AFTER. does this help? :)

[saxenankit]

1989 was WHEN the Berlin wall was demolished, not AFTER. does this help? :)

It does Tim, thanks

[jnelson0612]

Thanks Tim.