What does a pericentric inversion involve?

A pericentric inversion involves the rearrangement of a chromosome where a segment of the chromosome is inverted, and this inversion spans the centromere. This structural change affects the position of the centromere, which is the constricted region of a chromosome that separates the two arms. In pericentric inversions, both arms of the chromosome are involved in the inversion, making the presence of the centromere integral to the definition. This is what distinguishes a pericentric inversion from a paracentric inversion, where the inversion does not involve the centromere and only a single arm of the chromosome is involved. Thus, the correct choice accurately reflects the nature of pericentric inversions.