The fluoride concentration of human milk ranges from:: (A) 5-10 µg/L, (B) 2-8 µg/L, (C) 3-12 µg/L, (D) 2-10 µg/L
Answer is A. Fluoride concentration of human milk ranges from 5-10 µg/L. 
These levels are found in nursing mothers living both in non-ﬂuoridated and ﬂuoridated areas. 
Cow's milk contains 30-60 µg/L of ﬂuoride.
Essentials of preventive and community dentistry 
Soben Peter 5th edition