The result of which expression will best estimate the actual product of (-3/4)(3/5)(-6/7)(5/6)?

. (-1)(1/4)(-1)(-1)
. (-1)(1/2)(-1)(1)
. (-4/2)(3/2)(-2/5)(5/2)
. (-3/4)(-3/4)(- 1/5) (1/2)