Which sets of numbers are closed under addition?

choose all answers that are correct.

a.
{0, 2, 5, 8}

b.
even integers

c.
rational numbers

d.
{0}
plzz ?

false

step-by-step explanation:

the reason i say this is because for a certain length of sides you can pick any two and the length is wither equal or greater than the third side and in this case it's not.

3 + 5 = 8

8 is smaller than 9 which is the third side.

hope this : )