#### Answer

a). $(4) 129^{\circ}$ is correct.
b). $14408\,\,kms$

#### Work Step by Step

a). Both places are at the same latitude.
Only longitudes are different. Hence, the smallest angular distance the fan has to travel $=151^{\circ}-22^{\circ}=129^{\circ}$.
(4) is correct.
b). $S=r\theta=6400 km \times \frac{129}{57.3}=14408kms.$