Which of the following gifts would be considered taxable income to the person receiving the gift?

Question $4$ options:

a$)$

$$5,000$ given to the taxpayer from his friend.

b$)$

A mobile home given to the taxpayer by his mother.

c$)$

A ski boat won by the taxpayer on the Price is Right.

d$)$

A Mustang GT given to the taxpayer by his brother.

e$)$

None of the above would be considered taxable.