What would scientists using classical, Newtonian physics expect to observe during the photoelectric effect?
A. That enough light of any frequency would cause electrons to flow
O B. That light above a certain frequency would not cause electrons to
flow
O C. That no light would cause electrons to flow
O D. That light below a certain frequency would not cause electrons to
flow

A. That enough light of any frequency would cause electrons to flow.

Explanation:

A P E X

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.