1C is an enlarged, side view of the trigger assembly of FIG. 1A; FIG. 1D is an enlarged, side view of the embodiment of an end effector assembly of FIG. 1A showing relative extension of a monopolar element from a distal end of the end effector assembly; FIG. 2 is a side view of the trigger assembly is a second position for advancing a knife within the end effector assembly; FIG. 3 is a side view o