A child is considered to be doli-capax when he is:

Answer: Option B

In the context of the Indian Penal Code, a child is considered doli-capax when they are above 7 years but below 12 years of age. The term "doli-capax" refers to a child's ability to understand the nature and consequences of their actions, and therefore, to be held responsible for criminal conduct. According to Indian law, children below the age of 7 are considered incapable of committing a crime (doli-incapax) because they lack the necessary maturity and understanding. However, children above 7 years but under 12 may be considered capable of committing a crime if it can be proven that they had the sufficient maturity to understand the nature and implications of their actions.