Answer: The boy decided to venture out into the forest on his own.
Step-by-step explanation:
Venture has multiple meanings, one if which is to go on a journey that isn't really safe. The other refers to establishing a business which usually has some risk attached to it.
In the first option, the word venture was used appropriately as it describes the fact that the boy in question had gone on a journey (however short), a trip that has some sort of risk attached to it as forests can be dangerous.