The main reason for out-migration from Kerala is:

Lack of employment opportunities
Political instability
Natural disasters
Religious persecution Answer: a

The main reason for out-migration from Kerala is lack of employment opportunities. Kerala has a high literacy rate and a young population, but the state has been unable to create enough jobs to meet the demand. This has led to a large number of people leaving Kerala in search of work, mainly to the Gulf countries and other parts of India.

Political instability is not a major reason for out-migration from Kerala. The state has a stable democratic government and has not experienced any major political upheavals in recent years.

Natural disasters are also not a major reason for out-migration from Kerala. The state is located in a relatively safe region and does not experience many natural disasters.

Religious persecution is not a major reason for out-migration from Kerala. The state is a secular state and all religions are tolerated.

In conclusion, the main reason for out-migration from Kerala is lack of employment opportunities.