試題詳解

3. In computer science, numbers can be represented as either signed or unsigned. Which of the following statements accurately describes a difference between signed and unsigned numbers?
(A) Unsigned numbers can represent both positive and negative values, whereas signed numbers can only represent positive values.
(B) Signed numbers use a special“sign bit”at the least significant position to indicate whether the number is positive or negative, while unsigned numbers use this bit to extend their range of positive values.
(C) The range of values that can be represented by signed and unsigned numbers of the same bit length is the same, but signed numbers use a different encoding to represent negative values.
(D) Unsigned numbers are always larger than signed numbers because they use an extra bit to represent the magnitude of the value.
(E) Signed numbers use one bit to indicate the sign (positive or negative) of the number, allowing them to represent both positive and negative values. Unsigned numbers do not have a sign bit and can only represent positive values or zero.