Answer:
The protonated form is predominant when aspirin is absorbed more readily. The ratio of conjugate base to acid is 1 to 100.
Explanation:
Aspirin is more readily absorbed when it is protonated, that is when pH is lower than pKa (<em>more H⁺ available in the medium</em>). We can confirm this using Henderson-Hasselbalch equation for pH = 1.5:

When aspirin is absorbed more readily the ratio of conjugate base to acid is 1 to 100, being the acid the <em>predominant</em> form.
Answer:
Option B. Decreasing the temperature of the solvent
Explanation:
Solubility is mostly enhanced by increasing the temperature of the solvent or solution. This means that am increase in temperature will increase the solubility and decreasing the temperature will decrease the solubility.
The mass of 165.0 g sample that remains after 90.0 minutes is 5.16 grams
calculation
lambda㏑2/18= 0.0385
m(t)= 165 x e( 0.0385 x90) =5.16g