Option 3 is correct, i.e. Formic acid.

• Formic acid is the other name of Methanoic acid.
• The scientific name of HCOOH is formic acid.
• An acid is a compound that produces hydrogen ion when it dissolved in solution. The acidic property depends on the concentration of the Hydrogen ion in the solution.
• H+ ion cannot exist alone. It always conjugates with the water and forms hydronium ion(H³O+).
• If the concentration of H+ ion is more then it is called the Strong acid. Example: Hydrochloric acid(HCl), Sulphuric acid(H2SO4), Nitic acid(HNO3), etc.
• It the concentration of H+ ion is less then it is called the weak acid. Example: Acetic acid(CH3COOH), Carbonic acid(H2CO3), etc.