Ans. is 'a' Drug X will be available more in tissues In the question drug X has 150 times lower affinity to bind with albumin than drug Y and it is clearly given in the book that highly plasma protein bound drugs are largely restricted to the vascular compartment and tends to have lower volume of distribution. So it is clear that volume of distribution of drug X will be greater than drug Y and thus it will be more available to the tissue.Now don't get confused with the option "Free concentration of drug X in blood will be more," Make it clear that free concentration of the drug does not depend upon the plasma protein binding.The other clinically significant implications of plasma protein binding are :Bound fraction is not available for action. However, it is in equilibrium with the free drug in plasma and dissociates when the concentration of the latter is reduced due to elimination *.High degree of protein binding generally makes the drug long acting, because bound fraction is not available for metabolism or excretion*.Highly protein bound drugs are not removed by hemodialysis*.