Which one of the five pillars of islam refers to giving to the poor and needy?

alms
prayer
faith
pilgrimage

The correct answer is - alms.

The alms is the pillar that is referring to giving to the poor and needy. It is practiced by lots of Muslims, and it is considered as an act of solidarity towards the followers of the faith that are in dire need of it. This includes giving money, food, and clothing, though occasionally it may even include shelter. It can be performed in person when some people go to the people that they want to give something as aid, to invite some person in need or that is poor at their homes, or it goes as donations in the mosques which afterwards take the responsibility to deliver them to the poor and in need.

b) they want the land taken away from the wealthy landowners and given to peasants.

you didn't list the options. however, a few communist countries today are: the people's republic of china, north korea, and cuba.