The appropriate response would be British physicist, Sir Joseph John Thomson OM PRS. He was an English physicist and Nobel Laureate in Physics, credited with the disclosure and known of the electron; and with the revelation of the main subatomic particle.
The answer to your question is option b, a base. This is because the question clearly tells you that one reactant is an acid. Then, it tells you that an acid plus something gives you a salt and water, as products
From background knowledge, we know that a base plus acid gives you a salt and water. The hydroxide ions from the base neutralise the hydrogen ions from the acid, which gives you water ( as it has a pH of 7).
Therefore, your answer is b, a base
Copper has all those characteristics and even works on a Notatem scale.
Answer : The final number of moles of gas that withdrawn from the tank to lower the pressure of the gas must be, 0.301 mol.
Explanation :
As we know that:

At constant volume and temperature of gas, the pressure will be directly proportional to the number of moles of gas.
The relation between pressure and number of moles of gas will be:

where,
= initial pressure of gas = 24.5 atm
= final pressure of gas = 5.30 atm
= initial number of moles of gas = 1.40 moles
= final number of moles of gas = ?
Now put all the given values in the above expression, we get:


Therefore, the final number of moles of gas that withdrawn from the tank to lower the pressure of the gas must be, 0.301 mol.