Expansion of Forest in Veluwe, Netherlands at the Expense of Heathland

Expansion of forest in Veluwe, Netherlands at the expense of heathland has occurred primarily as a result of

A) reduction of grazing pressure as native herbivore populations were decimated by hunting.
B) changing climates due to the greenhouse effect.
C) new legal restrictions on land use.
D) reductions in sheep farming as Australian wool became less expensive.
E) reductions in sheep farming as young people left family farms for other careers.