The correct option is C B, A, C, D
In meiosis, the following processes occur in sequential order:
Synapsis is the pairing of two homologous chromosomes that occurs during meiosis.
Chromosomal crossover (or crossing over) is the exchange of genetic material between homologous chromosomes that results in recombinant chromosomes during sexual reproduction.
The chiasmata are thought to be the points where two non-sister chromatids exchange genetic material during chromosomal crossover during meiosis The chiasmata become visible during the diplotene stage of prophase I of meiosis I, but the actual "crossing-over" of genetic material is thought to occur during the previous pachytene stage. When tetrads, which are composed of two pairs of sister chromatids, begin to split the only points of contact are at the chiasmata.
It is followed by disappearence of nucleolous.
So, the correct answer is option C.