The correct option is B Crypts of lieberkuhn
Succus entericus is secreted by the intestinal glands of Crypts of Lieberkuhn. Enzymes of succus entericus act on the partially digested food and convert them into final digestive products.
Payer's patches are cluster of subepithelial lymphoid follicles in intestine.
Auerbach's plexus is a group of ganglia that runs through out the gastrointestinal tract.
Brunner's gland secrete mucin, which protects the mucosa of intestine from acidic stomach content.
So, the correct answer is- option d.