What effect has migration had on modern europe

For countries/ cities that are losing people there will be fewer people to housed and fed.
and reduces pressure or competition on jobs and resources.
 
For countries/cities  that are gaining people there will be more competition for skilled jobs(if the migrants are young and skilled) or high labour jobs  if the migrants are not very skilled.
This means that the population density will increase and more people will need to be fed and housed. This then creates a diversity in the communities which can have both negative and positive impact. 

Answerepicenter;

The shia sect of islam is primarily different from sunni islam in the belief that the first legitimate imam following muhammad was imam ali. unlike the three caliphs that succeeded muhammad, ali was part of muhammad's clan (related to him). major shia caliphates include the fatimid and safavid caliphates.  the answer will be option c. shia read more on