Asurfactant (reduces/increases) the surface tension of water and tends to (promote/inhibit) emulsification.

Surfactants reduces surface tension of water and promotes emulsification.

Explanation:

Surfactant is generally an organic molecule or compound that is amphiphilic in nature. Surfactants can act perform as emulsifiers, detergents, foaming agents, dispersants and wetting agents.

Surfactants decreases the surface tension between the solid and liquid, gas and liquid and two liquids and can acts as emulsifying agents, cleaning agents, dispersing agents, foaming and anti-foaming agents.

the man is bald so he has no hair to get wet

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.