Misoprostol is a prostaglandin analog (PGE2) that acts on the stomach to promote mucus protection of the stomach lining, but also acts in the uterus to encourage contraction, which makes it useful for abortion.

Going through other answer choices:

Bismuth and Sucralfate is used for ulcer healing or travelers diarrhea, it provides physical protection by binding to the ucler base and allows bicarb secretion to establish pH gradient in mucous layer.

FamotiDINE is a H2 receptor blocker

Omeprazole is a PPI and increases risk of C diff infxn, and decreases Mg and Ca absorption (can cause fx in elderly)