A. Membrana granulosa is a layer of granulosa cells which cover primary oocytes and form structures known as primordial follicles.
B. Cumulus ovaricus is a cluster of cells surrounding oocyte in Graafian follicle and even after ovulation. The inner most layer of cumulus cells give rise to Corona radiata which is adjacent to protective layer of ovum, zona pellucida.
C. Theca interna is inner layer of ca follicles.
D. Theca externa is outer layer of ca follicles.
Hence, Corona radiata is derived from Cumulus ovaricus.
So, correct answer is 'Cumulus ovaricus'.