A constant current flows from $A$ to $B$ as shown in the figure. What is the direction of current in the circle?

The problem describes a straight wire carrying a constant current from A to B. A circular loop is placed in the vicinity of this wire. According to the principle of electromagnetic induction, a current is induced in a closed loop only if there is a change in the magnetic flux linked with the loop. Since the current in the wire is constant, the magnetic field produced by it is also constant. Consequently, the magnetic flux through the circular loop remains constant over time. By Faraday's law of induction, the induced electromotive force is given by $\varepsilon = -\dfrac{d\phi}{dt}$. Since the magnetic flux $\phi$ is constant, $\dfrac{d\phi}{dt} = 0$, which implies that the induced electromotive force is zero. Therefore, no current is induced in the circle.

Answer: None of the above