The correct answer is B. Structural unemployment.
Structural unemployment is caused by mismatch whereby the skills which are between workers can offer in an economy and the skills which workers demand.
Some major categories of unemployment include classical unemployment, cyclical unemployment, involuntary unemployment and fictional unemployment.
Structural unemployment can be caused by being unable to afford relocation, unable to sell a house, decision not to relocate, having no decision to pursue job training or further education.