The graph gives the variation of magnitude of magnetic field (B) that exists throughout a conducting loop. with direction of the field perpendicular to the plane of the loop. The regions of graph according to magnitude of emf induced in decreasing order is:

$b>d>c=a$

The correct answer is Option (4) → $b>d>c=a$

Magnetic field in the region C is constant. Thus, no emf will be induced in that region.

Also, there exists no magnetic field in region A. Thus, no emf will be generated.

$⇒c=a=0$

Now,

Slope in region B is much greater than region D which suggest that the change in magnetic flux is greater in region B and thus emf will be greater.

$∴b>d<c=a$