Cousin Throckmorton has gone into hiding to escape online publicity. He has taken a room in a downtown hotel under the alias C and nervously reveals the room number to trusted family members only by telephoning them and playing a secret tone, whose waveform reveals the curve y = f(x) shown below. Only you know that CT's room number is the 4-digit sequence b1b2b3b4 in which each digit bk satisfies bk = ( (2) sin(kr) dat, k = 1,2,3,4. Use the given information to find CT. He is counting on you.