Impact Window and Door Incorporated manufactures and sells storm windows. Impact Inc. also provides installation service for the windows. The installation process does not involve changes in the windows, so this service can be provided by other vendors. Impact Inc. enters into the following contract on March 1st, 2022, with a local homeowner. The customer purchases windows for a price of $4,700 and chooses Impact Inc. to do the installation. Impact Inc. charges the same price for the windows irrespective of whether it does the installation or not. The price of the installation service is estimated to have a fair value of $1,200. The customer pays Impact Inc. $4,000 (which equals the fair value of the windows) on April 15th, 2022. Upon satisfactory installation, the customer will pay the remaining balance owed. The windows are delivered on April 15th, 2022 and Impact Inc. completes installation on April 20th, 2022. a) Impact Inc. has = performance obligation(s) under the contract. (b) Impact Inc. should recognize revenue on March 1st. (c) The amount of revenue (rounded to the nearest dollar) that should be allocated to the windows is $ to the installation is $