In the Electron Double- Slit Experiment with Electrons, What Happens

Multiple Choice

In the electron double- slit experiment with electrons, what happens when a detector is used to determine through which slit the electron actually passes?

A) The pattern on the screen suddenly becomes a non- interference pattern.
B) The pattern on the screen suddenly becomes an wave- interference pattern.
C) Batman arrives.
D) The electron then acquires both a precise velocity and a precise position.
E) The electron suddenly jumps into a state of higher energy.