The Hamiltonian of a two-level quantum system is 𝐻=12ℏ𝜔([1,1],[1,-1]). A possible initial state in which the probability of the system being in that quantum state does not change with time, is

(a) (𝑐𝑜𝑠(𝜋4)𝑠𝑖𝑛(𝜋4))

(b) (𝑐𝑜𝑠(𝜋8)𝑠𝑖𝑛(𝜋8))

(c) (𝑐𝑜𝑠(𝜋2)𝑠𝑖𝑛(𝜋2))

(d) (𝑐𝑜𝑠(𝜋6)𝑠𝑖𝑛(𝜋6))