Question 4 (1 point) Given that the following code has executed, what is the value of mystery? If your answer is a string, surround it with single quotes. If it is a number, just write the number. If it is a Boolean, write either True or False with no quotes. If this code won't work (crashes or infinite loop), write error with no quotes. string1 = 'I am 4 dogs!' mystery = for i in range (len (string1)): mystery += 3tr (1)