Which of the following is equivalent to the real part of eze^{z}ez where z=a+biz = a + biz=a+bi?
eacos(b)e^a \cos(b)eacos(b)
ebcos(a)e^b \cos(a)ebcos(a)
easin(b)e^a \sin(b)easin(b)
cos(a)+isin(b)\cos(a) + i\sin(b)cos(a)+isin(b)