Which of the given statements is incorrect about Clusters of orthologous groups?

• A. Paralogs may include a best hit or a high-scoring match of one of the sequences by another, but the reciprocal match can have low similarity that does not have to be significant
• B. Paralogs defined by sets of three matching sequences in the selected organisms were kept separated from the clusters
• C. Orthologous pairs were first defined by the best hits in reciprocal searches
• D. To produce COGs, similarity searches were performed among the proteomes of phylogenetically distinct clades of prokaryotes