It is risky to go beyond this barricade.

Answer: Option C

Stupid : having or showing a great lack of intelligence or common sense.
Adventurous : willing to take risks or to try out new methods, ideas, or experiences.
Hazardous : risky; dangerous.
Inadvisable : likely to have unfortunate consequences; unwise.
Risky : full of the possibility of danger, failure, or loss.

Synonym of Risky is Hazardous