The correct choice would be
(B) The magnets would be attracted to each other.
we know that like poles repel each other and unlike poles attract each other. hence when south pole of one magnet is placed near the north pole of other magnet, the two magnets attract each other due to interaction of magnetic fields of the two magnets. the magnetic field lines originating from north pole of one magnet ends at the south of other magnet
(a) 
The relationship between frequency and wavelength of an electromagnetic wave is given by

where
is the speed of light
is the frequency
is the wavelength
In this problem, we are considering light with wavelength of

Substituting into the equation and re-arranging it, we can find the corresponding frequency:

(b) 
The period of a wave is equal to the reciprocal of the frequency:

And using
as we found in the previous part, we can find the period of this wave:

Answer
Initial radius of the artery is (1.1 cm) / 2 = 0.55 cm
final radius of the artery is (0.90 cm) / 2 = 0.45 cm
initial velocity of the blood is 17 cm/s
Using equation of continuity is
A₁v₁=A₂v₂
π r₁² x v₁ = π r₂² x v₂
r₁² x v₁ = r₂² x v₂
0.55² x 17 =0.45² x v₂
v₂=25.39 cm/s
Bernoulli's equation is
rho is the density of blood = 1060 kg/m^3
Not enough information is given to answer this question.