This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Intrauterine growth restriction is defined as: 
Select and explain. 
A. There is oligohydramnios, B. The fetus weight less than 2.5 kg, C. Fetus fails to achieve growth potential, D. Duration of pregnancy more than 40 weeks
C: Fetus fails to achieve growth potential
Answer: C: Fetus fails to achieve growth potential 
Explanation: Fetus fails to achieve growth potential