It is "va" because the a in va represents he, she, and you (formal). He is going to the pool, so it is 'Mi padre va a la piscina con nosotros.'
How many different species of birds inhabit Costa Rica
The answer is (a) because compro is bought in Spanish and in the question it says “yesterday he bought the gifts for his mother” so bought would be the best answer. (B) is to buy I guess like I will buy chicken. And (c) is like they bought chicken. How I know this is well I speak Spanish I hope this helps!
Los conectores eléctricos se clasifican en tres tipos según sus extremos de terminación: conectores de placa a placa, conectores de cable/cable a cable/cable y conectores de cable/cable a placa.
Hope this helps