A watch goes fast by 15 minutes compared to the right time everyday. If it is corrected and set to the standard time at `12 O^(prime)c loc k` at noon, which of the following will be the time shown by it at 4:00 a.m. in the morning? (a) 3:45 a.m. (b) 4:10 a.m. (c) 4:15 a.m. (d) 4:30 a.m.