Code:
#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#pragma warning(disable:4996)
int menu();
void additionmenu();
void subtractionmenu();
void multiplicationmenu();




void main()
{
    int choice;
    //printf("You have selected the choice %d",menu());


    if (choice == 1)
    {
        printf("You have selected addition\n");
        additionmenu();
    }
    else if (choice == 2)
    {
        printf("You have selected subtraction\n");
        subtractionmenu();
    }
    else if (choice == 3)
    {
        printf("You have selected multiplication\n");
        multiplicationmenu();
    }
    else
    {
        printf("Invalid choice\n");
    }


    system("pause");
}
int menu()
{
    int choice;
    printf("1.addition\n");
    printf("2.subtraction\n");
    printf("3.multiplication\n");
    printf("Please choose either 1,2 or 3:");
    scanf("%d", &choice);
    return choice;


}


void additionmenu()
{
    char choice;
    printf("Please select the level");
    printf("A level 1");
    printf("B level 2");
    printf("C level 3");
    scanf("%c", &choice);
    if (choice == A)
    {
        printf("You have selected level 1\n");
        additionmenu();
    }
    else if (choice == B)
    {
        printf("You have selected level 2\n");
        subtractionmenu();
    }
    else if (choice == C)
    {
        printf("You have selected level 3\n");
        multiplicationmenu();
    }
    else
    {
        printf("Invalid choice\n");


    }


    int n1, n2, pcans, userans;
    int count = 1, mark = 0;
    


    do {
        srand((unsigned int)time(NULL));
        n1 = rand() % 10;
        n2 = rand() % 10;
        pcans = n1 + n2;


        printf("%d.%d+%d>", count, n1, n2);
        scanf("%d", &userans);
        if (userans == pcans);
        {
            printf("You are right\n");
            mark = mark + 5;
        }
        else
        {
            printf("You are wrong\n");
        }
        count++;
    } while (count <= 3);
    printf("Your score is %d", mark);
}



its show error at line 58,63,68,84,96 pls help me