Sentence Correction

When ethnic groups intermarry, it is likely to result in cognitive benefits; indeed, perhaps already having contributed to the Flynn effect, which has been the worldwide rise in average IQ score by as much as three points per decade over most of the past century.

A)When ethnic groups intermarry, it is likely to result in cognitive benefits; indeed, perhaps having contributed to the Flynn effect, which has been

B)The intermarriage of ethnic groups is likely to result in cognitive benefits and may indeed have contributed to the Flynn effect,

C)When ethnic groups intermarry, they are likely to result in cognitive benefits and may indeed have contributed to the Flynn effect, the name given to

D)Ethnic groups that intermarry will likely result in cognitive benefits; indeed, possibly having contributed to the Flynn effect,

E)The intermarriage of ethnic groups, likely to result in cognitive benefits, indeed have possibly contributed to the Flynn effect, the name given to


Please give me a reason of each options.

Thanks,

Shreyans

A)When ethnic groups intermarry, it is likely to result in cognitive benefits; indeed, perhaps having contributed to the Flynn effect, which has been

What does "it" refer to? Also, a semi-colon used this way must connect two independent clauses. What follows the semi-colon here could not stand on its own.

B)The intermarriage of ethnic groups is likely to result in cognitive benefits and may indeed have contributed to the Flynn effect,

Correct

C)When ethnic groups intermarry, they are likely to result in cognitive benefits and may indeed have contributed to the Flynn effect, the name given to

Does "they" refer to "ethnic groups?" This would mean that ethnic groups would result in cognitive benefits. Illogical.

D)Ethnic groups that intermarry will likely result in cognitive benefits; indeed, possibly having contributed to the Flynn effect,

Again, sounds as though the "groups" will result in cognitive benefits.

E)The intermarriage of ethnic groups, likely to result in cognitive benefits, indeed have possibly contributed to the Flynn effect, the name given to

Remove the modifier "likely to result in cognitive benefits" and that first clause is "The marriage of ethnic groups indeed have possibly contributed to the Flynn effect." Multiple problems here, but it's enough to see that it should be "The marriage of ethnic groups has..." (We can write, "The marriage has" or "The marriage may have")