To solve this problem, we need to analyze the acidic strength of nitrophenols compared to phenol.$\newline$Statement I: The acidic strength of monosubstituted nitrophenol is higher than phenol because of the electron-withdrawing nitro group.$\newline$• The nitro group $(NO_2)$ is a strong electron-withdrawing group due to its resonance and inductive effects.$\newline$• This increases the acidity of phenol by stabilizing the phenoxide ion formed after deprotonation.$\newline$• Therefore, monosubstituted nitrophenols are indeed more acidic than phenol.$\newline$Thus, Statement I is correct.$\newline$Statement II: o-nitrophenol, m-nitrophenol, and p-nitrophenol will have the same acidic strength as they have one nitro group attached to the phenolic ring.$\newline$• The position of the nitro group significantly affects the acidic strength.$\newline$• o-nitrophenol and p-nitrophenol have stronger acidic strengths than m-nitrophenol due to resonance stabilization.$\newline$• In o-nitrophenol, intramolecular hydrogen bonding also plays a role, affecting its acidity.$\newline$• Therefore, o-nitrophenol, m-nitrophenol, and p-nitrophenol do not have the same acidic strength.$\newline$Thus, Statement II is incorrect.$\newline$Analyzing the options:$\newline$• Option 1: Both Statement I and Statement II are correct. (Incorrect)$\newline$• Option 2: Both Statement I and Statement II are incorrect. (Incorrect)$\newline$• Option 3: Statement I is correct, but Statement II is incorrect. (Correct)$\newline$• Option 4: Statement I is incorrect, but Statement II is correct. (Incorrect)$\newline$Therefore, the correct option is Option 3.