Two statements, One Assertion and the other Reason, are given. Which one of the following is the correct option? Assertion: The acid strength of 4 compounds in the descending order is p-Nitrophenol > p-Methoxyphenol > Phenol > p- chlorophenol. Reason: Electron withdrawing groups increase the acid strength while Electron donating groups decrease the acid strength of Phenol and its derivatives.

The acid strength of substituted phenols depends on the electronic effects of the substituents. Electron withdrawing groups (EWG) stabilize the phenoxide ion through inductive (-I) and resonance (-M) effects, thereby increasing acidity. Electron donating groups (EDG) destabilize the phenoxide ion through inductive (+I) and resonance (+M) effects, thereby decreasing acidity.

Comparing the substituents:
1. p-Nitrophenol: $-NO_{2}$ is a strong EWG ($-I$ and $-M$ effects), making it the most acidic.
2. p-Chlorophenol: $-Cl$ is an EWG ($-I$ effect dominates over $+M$ effect), making it more acidic than phenol.
3. Phenol: Reference compound.
4. p-Methoxyphenol: $-OCH_{3}$ is an EDG ($+M$ effect dominates over $-I$ effect), making it the least acidic.

The correct descending order of acid strength is p-Nitrophenol > p-Chlorophenol > Phenol > p-Methoxyphenol. The assertion states the order as p-Nitrophenol > p-Methoxyphenol > Phenol > p-chlorophenol, which is incorrect. The reason correctly states that EWGs increase acid strength and EDGs decrease it.

Answer: Assertion is wrong but Reason is correct.