1. Write the dimensional formula of torque

Torque is $\tau = \text{force} \times \text{distance}$

Since $[\text{force}] = [M L T^{-2}],$ we get $[\tau] = [M L^2 T^{-2}].$

So torque depends on:

• mass with power $1$
• length with power $2$
• time with power $-2$

2. Use the rule for maximum percentage error

If a quantity $Q = A^a B^b C^c,$ then the maximum percentage error is $\frac{\Delta Q}{Q} \times 100 = \left(|a|\frac{\Delta A}{A} + |b|\frac{\Delta B}{B} + |c|\frac{\Delta C}{C}\right) \times 100.$

Here each reference standard of mass, length, and time has $5\%$ error.

Thus for torque: $\frac{\Delta \tau}{\tau} \times 100 = 1(5\%) + 2(5\%) + 2(5\%).$

3. Calculate

$5\% + 10\% + 10\% = 25\%.$

4. Final answer

Hence the net accuracy/error in measured torque is $\boxed{25\%}.$

So the correct option is B.