The event at metaphase-I which increases the genetic diversity is the:

Explanation

The correct answer is the random orientation of homologous chromosomes at the equator during metaphase-I. This process, known as independent assortment, results in different combinations of maternal and paternal chromosomes being distributed to the gametes, thus increasing genetic diversity. The formation of bivalents and the dissociation of the synaptonemal complex are important processes in meiosis but do not directly contribute to genetic diversity. The contraction of spindle fibers facilitates chromosome movement but does not affect genetic variation.