Explanation:
C
When stamen are united with each other the it is called synandrous condition. This condition is found in Benincasa (ash gourd) which is a member of family Cucurbitaceae.
Syngenesious is a condition, in which filament are free but anthers are fused together eg.- Ageratum, disc florets of sunflower.
Diadelphous is a condition in which stamens are united to form two groups. It is found in the member of the Fabaceae family.