Two Calling Conventions, Same Result

class Account:
    def __init__(self, balance):
        self.balance = balance

    def deposit(self, amount):
        self.balance += amount
        return self.balance

a = Account(100)
print(a.deposit(50))
print(Account.deposit(a, 25))
print(Account.deposit(30))

What does this print, in order, for the first two lines, and what happens on the third?

150, then 175, then None, because calling deposit on the class with one argument silently does nothing.

150, then 175, then a TypeError because deposit is missing the required amount argument.

150, then 175, then 205, since Account.deposit(30) deposits 30 into the same account.

150, then a TypeError on the second line, because Account.deposit cannot be called with an explicit instance argument.