In the Seismic Tomography Cross Section Below,where Is the Subducting

In the seismic tomography cross section below,where is the subducting Juan de Fuca Plate,considering that the subducting plate is much cooler than the surrounding material?

A) #4: blue blob at the far right side of the picture that extends straight down into the image
B) #2: blue blob at the left side of the picture that extends down at an angle into the image
C) #1: red blob at the far left side of the picture that extends straight down into the image
D) #3: red blob in the center of the picture that extends straight down into the image