An autotetraploid plant has 72 chromosomes, 4N= 72. Which of the following scenarios could be observed in Meiosis I?

a) 24 Trivalents
b) 18 tetravalents OR 36 Bivalents
c) 18 Bivalents and 24 Univalents
d) 18 trivalents and 36 Bivalents