A customer purchases an item from an e-commerce site. The e-commerce site must maintain proof that the data exchange took place between the site and the customer. Which feature of digital signatures is required?a. authenticity of digitally signed datab. integrity of digitally signed datac. nonrepudiation of the transactiond. confidentiality of the public key

Quick calculate the roi dollar amount and percentage for these example investments. a. you invest $50 in a government bond that says you can redeem it a year later for $55. use the instructions in lesson 3 to calculate the roi dollar amount and percentage. (3.0 points) tip: subtract the initial investment from the total return to get the roi dollar amount. then divide the roi dollar amount by the initial investment, and multiply that number by 100 to get the percentage. b. you invest $200 in stocks and sell them one year later for $230. use the instructions in lesson 3 to calculate the roi dollar amount and percentage. (3.0 points) tip: subtract the initial investment from the total return to get the roi dollar amount. then divide the roi dollar amount by the initial investment, and multiply that number by 100 to get the percentage.