To solve this problem, we need to match the types of inhibition with the given plots. Each plot characterizes a rate of reaction ("v") versus substrate concentration ("[S]") for different enzymatic reaction situations.

Let's analyze each plot and match it with the correct reaction type:

1. Plot (i): This plot shows a typical Michaelis-Menten curve where the reaction rate approaches a maximum velocity \( V_{\text{max}} \) as substrate concentration increases. Thus, this plot represents Michaelis-Menten kinetics.
2. Plot (ii): In this graph, the reaction rate increases to a maximum and then decreases as substrate concentration increases. This represents substrate inhibition, where excessive substrate concentration actually inhibits enzyme activity.
3. Plot (iii): This plot depicts a scenario where the presence of an inhibitor affects only the apparent affinity of the enzyme for the substrate, increasing the \( K_m \) value without affecting \( V_{\text{max}} \). This is characteristic of competitive inhibition.
4. Plot (iv): This curve shows a reduction in the \( V_{\text{max}} \) without affecting the \( K_m \), which is characteristic of non-competitive inhibition. Here, the enzyme's maximum rate is lowered regardless of substrate concentration.

Based on this analysis, we can match the reaction types with their plots as follows:

• P – iii: Competitive inhibition
• Q – ii: Substrate inhibition
• R – i: Michaelis-Menten
• S – iv: Non-competitive inhibition

Thus, the correct answer is: P – iii, Q – ii, R – i, S – iv.