in which of the following situations must a gift tax return be filed(assume all gifts are made in 2016)

a. a person gives his stepdaughter a wedding gift if a $25,000 check

b. a person gives his alma mater a gift by check for $25,000

c. a person gives his spouse (a U.S. citizen) a gift of $25,000

d. a person gives his church a gift of $25,000. this is the only gift given in 2015