To determine the correct statements regarding the use of different substances in emulsion paints, let's evaluate each statement individually:

1. Statement I: Pine oil is used as antifoaming agent in the emulsion paints.

Pine oil is indeed used as an antifoaming agent in emulsion paints. It helps to reduce the formation of foam during the mixing and application of paints. Therefore, this statement is correct.

1. Statement II: Protective colloids are used in the emulsion paints to decrease their stability.

Protective colloids are actually used to enhance the stability of emulsion paints, not to decrease it. They help in maintaining the dispersion of solid particles in the liquid, preventing coagulation or settling. Hence, this statement is incorrect.

1. Statement III: Driers having oxidizable oils are added to the emulsion paints to accelerate drying process.

Driers, which are often metallic soaps, are indeed added to paints to accelerate the drying process. They work by catalyzing the oxidation of oil components in the paint, thus promoting faster drying. This statement is correct.

Based on the above evaluations:

• Statement I is correct as pine oil is used as an antifoaming agent.
• Statement II is incorrect; protective colloids increase stability, not decrease it.
• Statement III is correct; driers with oxidizable oils are used to speed up drying.

Therefore, the correct statements are I and III.

Correct Answer: I and III