The affluence of most visiting Arabs is astonishing.

Answer: Option B

Ostentation : the pretentious or showy display of wealth and luxury, designed to impress.
Wealth : an abundance of valuable possessions or money.
Influence : the capacity to have an effect on the character, development, or behaviour of someone or something, or the effect itself.
Endeavour : try hard to do or achieve something.
Affluence : the state of having a great deal of money; wealth.

Synonym of Affluence is Wealth