Required information [The following information applies to the questions displayed below.] Grady received $8,800 of Social Security benefits this year. Grady also reported salary and interest income this year. What amount of the benefits must Grady include in his gross income under the following five independent situations? (Leave no answer blank. Enter zero if applicable.) a. Grady files single and reports salary of $13,600 and interest income of $400. Answer is complete and correct. Amount to be included b. Grady files single and reports salary of $23,650 and interest income of $750. Answer is complete but not entirely correct. Amount to be included $ 28,800 c. Grady files married joint and reports salary of $78,000 and interest income of $650. Amount to be included d. Grady files married joint and reports salary of $44,000 and interest income of $850. Amount to be included e. Grady files married separate and reports salary of $23,650 and interest income of $750. Amount to be included