Combining two real wave functions $\phi_{1}$ and $\phi_{2}$ the following functions are constructed: $\mathrm{A}=\phi_{1} +\phi_{2}, B=\phi_{1}+i \phi_{2}, C=\phi_{1}-i \phi_{2}, D=i\left(\phi_{1}+\phi_{2}\right)$ The correct statement will then be
(a)A and B represent the same state
(b)A and C represent the same state.
(c)A and D represents the same state
(d)B and D represent the same state.
Answer
SELF-PRACTICE — the source book printed no answer.
Nothing is invented here, so this question has no answer on record.