On 1/1/2011, Lego Construction Company signed a contract to build a custom garage for a customer and received $10,000 in advance for the job. The new garage will be built on the customer's land. To complete this project, Lego must first build a concrete floor, construct wooden pillars and walls, and finally install a roof. Lego normally charges stand-alone prices of $3,000, $4,000 and $5,000, respectively, for each of these 3 smaller tasks, if done separately. How many performance obligations exist in this contract? O a. 3 O b. 2 O c.0 O d. 1