Under the rules of constructive ownership:

a.if a partnership with two equal partners owns 10 percent of the stock in a corporation, each partner is treated as owning 5 percent of the stock in that corporation.

b.stock owned by the taxpayer's spouse, descendants, ancestors, or siblings is treated as owned by the taxpayer.

c.a taxpayer may be treated as owning stock that is actually owned by another person or entity in which the taxpayer has an ownership interest.

d.both a and c.

e.all of the above