Dialysing unit (artificial kidney) contains a fluid which is almost same as plasma except that it has

1. high glucose

2. high urea

3. no urea

4. high uric acid

(c) The dialysing unit (fluid) has the same composition as that of plasma except the nitrogenous waste (urea).
Other options are wrong, as dialysing unit will not have high glucose, high urea or high uric acid.