its Qt'....
D=Qt'
T=Qd (XOR) T
we have to find next state of Qt and Qd
just check on what parameters they depend
Qt depends on T which i have mentioned above depends on Qd and T
Qd depends on D which as stated above depends on Qt'
draw truth table for Qd and Qt first then accordingly write their next state seeing D and T..try if any doubt ask,,,