H\(_3\)PO\(_4\) (phosphoric acid) is acidic in solution. It's a weak acid, meaning it doesn't fully dissociate into ions when dissolved in water. Phosphoric acid can donate three hydrogen ions (H\(^+\)) to water, making it a triprotic acid. Also, ammonium chloride (NH\(_4\)Cl) is acidic in solution. This is because NH\(_4\)Cl is formed from a strong acid (HCl) and a weak base (NH\(_3\)), and the ammonium ion (NH\(_4\)\(^+\)) acts as a weak acid when dissolved in water, causing the solution to have a lower pH than 7. 

Both H\(_3\)PO\(_4\) (phosphoric acid) and NH\(_4\)Cl(ammonium chloride) are acidic in solution, but we can say NH\(_4\)Cl is more acidic due to the hydrolysis of the ammonium ion. H\(_3\)PO\(_4\) (phosphoric acid) is acidic in solution as well. It's a weak acid, meaning it doesn't fully dissociate into ions when dissolved in water.

Consequently, we can go for option B.