Suppose that last year the equilibrium price and the quantity of goodXwere $10 and 5 million pounds. Because of strong demand this year, the equilibrium price and the quantity of goodXare $12 and 7 million pounds, respectively. Assuming that the supply curve of goodXis linear, what happened to producer surplus in the market?

AProducer surplus increased from $12.5 million to $49 million.

BProducer surplus increased from $12.5 million to $24.5 million.

CProducer surplus increased from $3 million to $7 million.

DProducer surplus increased from $4.2 million to $5.6 million.

Explain with diagram.