Explanation:

Let’s review each statement:

1. Removing all the leaves from a plant will reduce water flow up the stem.

- True. Leaves drive transpiration, so removing them lowers the pull of water.

2. Covering both sides of leaf with plastic film will reduce both stomatal and cuticular transpiration.

- True. Plastic blocks both pathways for water vapor loss.

3. Injecting detergents (which lower the surface tension of water) into the xylem of trunk could prevent water from reaching upper branches.

- True. Lowered surface tension can cause air bubbles (embolisms), disrupting water transport.

4. Through most of its route in a plant, water moves by diffusion either along cell walls or across protoplasts.

- False. Water mainly moves by bulk flow (mass flow) due to pressure differences in xylem, not just by diffusion.

Now check the options:

- Option 1, 2, & 4: Includes statement 4 (false).

- Option 2, 1, 3, & 4: Includes statement 4 (false).

- Option 3, 1, 2, & 4: Again, includes 4 (false).

- Option 4, 1, 2 & 3: Contains only correct statements.

Correct answer:

Option: 4, 1, 2 & 3