Well West Indies better beat South Africa or India to be sure of their spot in the quarter finals. They better not lose to any of these teams too badly either because the last spot may be determined by net run rate.
Even if WI lose to South Africa and India, as long as they beat UAE they should still qualify. In order for Pakistan to jump ahead of WI and Ireland, they will need heavy wins against Zimbabwe and UAE and beat South Africa and Ireland.
Matches remaining in Pool B:
South Africa v WI
Pakistan v Zimbabwe
South Africa v Ireland
Pakistan v UAE
India v WI
South Africa v Pakistan
Zimbabwe v Ireland
India v Ireland
South Africa v UAE
India v Zimbabwe
WI v UAE
Ireland v Pakistan
Despite Ireland's strong start, their inferior net run rate may end up costing them a place in the quarter-finals. The good news for WI is that Ireland and Pakistan have to play each other in the last match which will further weaken their net run rate (barring a rain out).