Job is to find info which is inferred and not directly mentioned in the passage:
A → stated in the para
B → we only know that sending weak electrical signals results in nervous activity in the brain but got no clue about the intensity of that activity.
D–> Is directly stated
E → As in para it say’s that scientist discovered electroreceptor then we can’t say they were ensuring that only electroreceptors were responding
That left us with no choice but to go with C