Two identical straight wires are stretched so as to produce 6 beats/s when vibrating simultaneously. On changing the tension slightly in one of them, the beat frequency remains unchanged. Denoting by T1,T2 the higher and the lower initial tension in the strings, then it could be said that while making the above changes in tension (JEE 1991)
a. T2 was decreased
b. T2 was increased
c. T1 was decreased
d. T1 was increased