Answer : Option B

Explanation :

ASCII to Extended ASCII characters (8-bit system) and ANSI Code: In the 1960s, a need for standardization led to ASCII, which is a 7-bit system. But later almost everything was done in an 8-bit system. With 7 bits, 128 numbers (0-127 in decimal notation) are available to code characters. A bit is a binary digit which can have either two values, on or off. Seven bits can have 2^7 or 128 possible unique values. ASCII was soon expanded to an 8-bit system that has 256 code points, 0-255 (8-bit corresponds to 2 ^ 8 ie. 256 possibilities). There are many variants of Extended ASCII characters (8-bit system) to cover regional characters and symbols. One example is the extended ASCII characters which includes various letters needed for writing languages of Western Europe and certain special characters.

Source : wikipedia.org