a) David wanted to consume three servings of the beverage over 24 hours. He considered either Regime 1: consuming one serving, wait for x hours, then consume the second serving, then wait for y hours, then consume the third serving. Regime 2: consuming two servings at one go and wait for z hours, before consuming the third serving.

i) Estimate the minimum values for x, y, x + y and z. Explain your reasoning in arriving at your estimates.

ii) Before consuming the third serving, both Regime 1 and 2 would have exposed David to the same total amount of Toxicant A. So the total waiting time should be the same. Explain why your (x+y) is not equal to z. Advise David on which Regime is the safer option.

b) Toxicant A in the beverage is processed by the liver and its metabolites are soluble in bile. Describe concisely Toxicant A's absorption route, distribution, general metabolism reactions and finally excretion mechanism.

Question 3 Toxicant A is found in a beverage drink. The following graph shows the blood concentrations of a toxicant A in a typical person after consuming the beverage drink. Assume the time of absorption of toxicant A into blood circulation is negligible