The joint spin state of two spin s 12 particles 1square roo

The joint spin state of two spin s = 1/2 particles 1/square root 2 (|up arrow down arrow + | down arrow up arrow) is orthogonal to (1) | up arrow up arrow (2) | up arrow down arrow (3) 1/root over 2 (| up arrow down arrow - | down arrow up arrow)(4) | down arrow down arrow (5) none of the above

Solution

the answer of the above state is option 3