ANS:D - both (b) and (c).

In the given options: a) "Same velocity profile or equal eddy diffusivities" - This condition implies similarity in transport mechanisms for both mass and heat transfer, making the analogy applicable. b) "Thermal or pressure mass diffusion" - Mass diffusion due to thermal or pressure gradients parallels heat transfer through diffusion, making the analogy applicable. c) "Viscous heating or chemical reaction" - Viscous heating and chemical reactions do not have direct analogs in mass transfer, thus breaking down the analogy between mass and heat transfer. Therefore, the correct option is: both (b) and (c).