in which of the following scenarios does the taxpayer fail to meet the residency test for etc purposes?

a. a taxpayer whose child lie with him for 5 month and 28 days.

b.a taxpayer whose eligible foster child lived with him all year

c. a taxpayer whose child lived with him all year. he and his spouse separated on may 29.

d.a taxpayer who's is 64 years old and lived in the usa for more that half of the year.