In Making a Backward Pass Through a Network, Activity L

In making a backward pass through a network, activity L has an activity time of 4 and immediately precedes activities M, P, and T. The late start times for activities M, P, and T are 22, 17, and 27, respectively. The late finish times for activities M, P, and T are 29, 27, and 33, respectively. What is the late start time for activity L?

A) 13
B) 17
C) 22
D) 33
E) 37