Assume Two Threads Share a BankAccount Object with Balance of Zero

Assume two threads share a BankAccount object with balance of zero (0) , and that the BankAccount class provides deposit and withdraw methods and has a ReentrantLock named myLock, as shown below. Thread one deposits $10 ten times and, concurrently, thread two withdraws $10 ten times. Which statement regarding the balance after all thread calls is definitely true?
Public void deposit(int dollars)
{
MyLock.lock()
Int newBalance = balance + dollars;
System.out.println("depositing") ;
Balance = newBalance;
MyLock.unlock()
}
Public void withdraw(int dollars)
{
MyLock.lock()
Int newBalance = balance - dollars;
System.out.println("withdrawing") ;
Balance = newBalance;
MyLock.unlock()
}

A) The balance could be zero or positive.
B) The balance is zero.
C) The balance could be zero or negative.
D) The balance is positive.