According to computer models, most coastal areas will experience what effect of global warming

increased flooding .

all late but that's the answer :)

Most of the coastal regions will experience increased flooding because of global warming.  

Due to global warming, the levels of the sea will rise mainly due to two reasons. First, with the increase in temperature, huge amounts of ice in the polar caps will melt, increasing the volume of water in the oceans. Secondly, the substances seem to expand when it gets heated, that is, known as thermal expansion.  

Thus, if the average temperature of the Earth rises, the water in the ocean will expand, leading to rising sea levels. One prime influence of rising sea levels is that coastal regions will encounter with more flooding, mainly due to storm surges at the time of typhoons or hurricanes.  

b would be the right answer