Brunner's glands are found in which of the following layers?

Give scientific reason:
$(1)$ Heterodontic dentition is seen in human beings.

Match the names of glands listed under column $-I$ with the location given under column $-II$, choose the answer which gives correct combination of the alphabets of the two columns.

Column $-I$ (Glands)	Column $-II$ (Location)
$(A)$ Crypts of Lieberkuhn	$(p)$ Loop of duodenum
$(B)$ Pancreas	$(q)$ Stomach
$(C)$ Adrenal gland	$(r)$ Intestine
$(D)$ Gastric gland	$(s)$ Kidney

In the empty stomach,mucosal folds appear. They are called

Identify the location and function of the following:
$(1)$ Villi
$(2)$ Oxyntic cells

Peyer's patches are found on the ileum in