JEE Main 2023 Physics question

A 10 C charge is divided into two parts and placed at 1 cm distance so that the repulsive force between them is maximum. The charges of the two parts are:

• (A)7 C, 3 C
• (B)8 C, 2 C
• (C)5 C, 5 CCorrect
• (D)9 C, 1 C