Step-by-step Solution:

Let V be Vina's age, S be Shekhar's age, and C be Charu's age.

The given condition: "the total ages of Vina and Shekhar is 15 years more than the total age of Shekhar and Charu" translates to:

V + S = (S + C) + 15

Simplifying by subtracting S from both sides:

V = C + 15

Thus, V - C = 15, meaning Charu is 15 years younger than Vina.

Answer: (C) 15