Assume There Are Three Hardware Stores,each Willing to Sell One

Assume there are three hardware stores,each willing to sell one standard model hammer in a given time period.House Depot can offer their hammer for a minimum of $7.Lace Hardware can offer the hammer for a minimum of $10.Bob's Hardware store can offer the hammer at a minimum price of $13. Given the scenario described,if the market price of hammers increased from $8 to $11:

A) total producer surplus would increase by $3.
B) total producer surplus would increase by $6.
C) total producer surplus would increase by $9.
D) total producer surplus would increase by $4.