Arrange the following plants in descending order based on the number of locules in their ovaries

I) Pisum            

II) Citrus

III) Smilax                  

IV) Petunia

Citrus belongs to Rutaceae ( number of locules in ovary are many), Smilax belongs Liliaceae ( number of locules present in ovary are 3), Petunia belongs to solanaceae (number of locules present in ovary are 2),   (1)Pisum belongs to fabaceae ( unilocular ovary)