In binary systems the sign of a number is indicated by

A$)$ placing a negative sign in front of the number

B$)$ including a sign bit along with the magnitude bits

C$)$ inverting the bits if the number is negative

D$)$ using a $0($zero$)$ bit in front of negative numbers

When performing binary addition using the $2\text{'}$s complement method, an overflow can occur if

A$)$ both numbers have the same magnitude

B$)$ both numbers have the same sign

C$)$ the second number is much greater than the first

D$)$ one number is negative and the other is positive