GMAT Sentence Correction (SC) | Re: When ethnic groups intermarry, it is likely

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,