Magnetic Field of Straight Wires question from MHT CET 2025 (26 Apr, Shift 1)

Answer: (d)

1. Infinite straight wire at distance $r$: $\frac{\mu_0 I}{2\pi r}$, out of the page (current right, O above).
2. Circular loop (clockwise): $\frac{\mu_0 I}{2r}$, into the page.
3. $B = \frac{\mu_0 I}{2r} - \frac{\mu_0 I}{2\pi r} = \frac{\mu_0 I}{2\pi r}(\pi - 1)$
4. So the answer is (d).