In the experiment to show that light is necessary for photosynthesis, some of the steps of the experiment deal with the following activities.

I. Starch reacts with iodine and gives blue-black colour

II. Chlorophyll is dissolved in ethanol

III. Hot water makes leaf tissue soft The correct sequence of these steps is

(1) I–II–III

(2) II–III–I

(3) III–II–I

(4) I–III–II