Question: animate transparency

I'm trying to animate transparency, here's are the plots:

A :=tranz-> plot3d(-2/sqrt(x^2+y^2)+5/sqrt((x-1.6)^2+y^2), x = -5 .. 5, y = -5 .. 5, view = [-5 .. 5, -5 .. 5, -5 .. 5], transparency = tranz) end proc;
B := sphere([0, 0, 0], 2*(1/10), color = magenta, style = patchnogrid):
C := sphere([1.6, 0, 0], 5*(1/10), color = green, style = patchnogrid);
E := plot3d(0, x = -5 .. 5, y = -5 .. 5, view = [-5 .. 5, -5 .. 5, -5 .. 5], style = wireframe, shading = zgrayscale):

here I am displaying them without a problem:

display(A(.5), B, C, E, scaling = constrained, view = [-5 .. 5, -5 .. 5, -5 .. 5], axes = normal)

here I am trying to animate the transparency in plot A to no avail :( :

animate(display, [A(tranz), B, C, E, scaling = constrained, view = [-5 .. 5, -5 .. 5, -5 .. 5], axes = normal], tranz = 0.1 .. 0.9)
Error, (in plot3d) expecting option transparency to be of type {"default", realcons} but received tranz

if you guys could help me find where I'm going wrong I'd be super grateful :D

thanks everyone.

Best,

-Mike