Clyde is a cash-method taxpayer who reports on a calendar-year basis. This year Paylate Corporation has decided to pay Clyde a year-end bonus of $2,100. Determine the amount Clyde should include in his gross income this year under the following circumstances: (Leave no answer blank. Enter zero if applicable.)

a. Paylate Corporation wrote the check and put it in his office mail slot on December 30 of this year, but Clyde did not bother to stop by the office to pick it up until after year-end.

b. Paylate Corporation mistakenly wrote the check for $320. Clyde received the remaining $1,780 after year-end.

c. Paylate Corporation mailed the check to Clyde before the end of the year (and it was delivered before year-end). Although Clyde expected the bonus payment, he decided not to collect his mail until after year-end.

d. Clyde picked up the check in December, but the check could not be cashed immediately because it was postdated January 10.