A)The son .
B)The father .
C)The mother
D)Aunt Louise
原文：
W:I don't know how you can eat so much yet never put on any weight,son.Your father's got thesame luck.I can't take a bite without calculating how many calories I am taking.
M:but remember Aunt louise, Mom?She ate a lot and never gained a pound.
Q:Who is worried abort qaining weight?