I need help with my test and don’t understand how to complete it.

Which would not reduce the amount of green house gasses in the air

Does work output exceed work input when a machine is used? a) yes, it does, as machines create energy. b) it depends on the type of machine used. c) no, it doesn’t, as machines are inefficient. d) no, it doesn’t, as machines cannot create energy.

Because light travels in a straight line and casts a shadow, isaac newton hypothesized that light is