Inversion is a type of mutation which occurs in the chromosome structure in which the chromosome region breaks at two points and the region between the break and rotates to 180°. The rotated region after rotation rejoins with the end of the chromosomes.
Sometimes these break occurs in the region of the gene and the inversion of the sequence of the gene proves a lethal mutation like in the case of haemophilia in humans.
Thus, Chromosomal inversion is the correct answer.
