Given the following declaration: int num; int *ptr1; int *ptr2; double *ptr3; Mark the following statements as valid or Invalid. If a statement Is Invalid, explain why. (1 point per problem) Ptr1 = ptr2; num = ptr1; ptr3 = ptr1;*prt3 = *ptr2; *ptr1 =*ptr2; num = *ptr2; ptr1 = &ptr2; ptr1 = # num = &ptr1