The angle of contact, also known as the contact angle, is the angle formed between a liquid droplet and the solid surface it is in contact with. It is an important parameter that determines the wetting behavior of the liquid on the surface. The angle of contact can be either acute (less than 90 degrees), obtuse (greater than 90 degrees), or right angle (equal to 90 degrees).

The wetting behavior of a liquid on a solid surface is influenced by two main forces: cohesion and adhesion. Cohesion refers to the intermolecular forces between the liquid molecules, while adhesion refers to the forces between the liquid and the solid surface.

When the angle of contact is acute, it means that the liquid droplet spreads out on the surface and wets it effectively. In this case, the adhesion forces between the liquid and the solid surface are stronger than the cohesion forces between the liquid molecules. This can be explained by the fact that the liquid molecules have a stronger attraction to the solid surface than to each other.

Explanation of the correct option:

a) Adhesion is more than cohesion

When the angle of contact is acute, the adhesion forces are more dominant than the cohesion forces. The liquid droplet spreads out on the surface, indicating a stronger attraction between the liquid and the solid surface. Hence, option A is the correct answer.

Explanation of other options:

b) Cohesion is more than adhesion:

This option is incorrect because an acute angle of contact implies that the adhesion forces are stronger than the cohesion forces.

c) Cohesion is equal to adhesion:

This option is incorrect because an acute angle of contact indicates an imbalance between adhesion and cohesion forces, with adhesion being stronger.

d) Adhesion and cohesion have no bearing with the angle of contact:

This option is incorrect because the angle of contact is a direct result of the balance between adhesion and cohesion forces. The angle of contact determines the wetting behavior of the liquid on the solid surface.

In conclusion, when the angle of contact of a liquid droplet is acute, it indicates that the adhesion forces between the liquid and the solid surface are stronger than the cohesion forces between the liquid molecules.