REQUEST ON F1 visa and OPT extension Programme

Hai Guys This Is Nithin

   I have applied to college A and College B with college A has one specialization and College B has another specialization and I received both I 20's . I got visa on college A but I don't want to study in that specialization so I want to transfer to college B with other specialization . Will be there any problems like OPT exension ..and others ?