When did Swat valley become part of Pakistan?

وادی سوات کب پاکستان کا حصہ بنی؟

28th July 1969

4th April 1969

29th June 1970

None of these

State of Swat was Established in 1849.
On 28 July 1969, General Yahya Khan announce full integration states of Chitral, Dir and Swat.