In unit-vector notation, what is the net torque about the origin on a flea located at coordinates (0, -4. 0 m, 5. 0 m) when forces F₁=−3. 0Nk and F₂​=2. 0Ne act?
a) τ=(−6. 0Nm) j+(15. 0Nm) k
b) τ=(6. 0Nm) j−(15. 0Nm) k
c) τ=(6. 0Nm) j+(15. 0Nm) k
d) τ=(−6. 0Nm) j−(15. 0Nm) k