(A) : A red object appears dark in the yellow light. 
(R) : The red colour is scattered least.

A red object looks red because it reflects only red colour and absorbs all other colours present in the white light. Hence, when red object is seen through yellow light then it absorbs yellow colour falling on its and appears dark. This assertion has got nothing to do with scattering. Also from Rayleigh's criteria of scattering.
Scattering ∝$\frac{1}{{\lambda }^4}$
(wavelength)  
Since red colour has a larger wavelength it is scattered least.