With respect to the ASCII character set, which statement correctly describes its size and inclusion of control characters in the 7-bit standard?
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Ais a subset of 8-bit EBCDIC
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Bis used only in Western Countries
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Cis version II of the ASC Standard
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Dhas 128 characters, including 32 control characters
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ENone of the above
Answer
Correct Answer: has 128 characters, including 32 control characters
Explanation
Introduction / Context:ASCII is a foundational 7-bit character encoding used widely in computing and networking. Knowing its size and composition helps when mapping text, control codes, and interoperability between systems.
Given Data / Assumptions:
- Standard ASCII uses 7 bits.
- Total possible codes with 7 bits: 128.
- Control characters occupy the lower range (commonly 0–31) plus DEL at 127 is often treated specially.
Concept / Approach:Identify the statement that matches the canonical description of ASCII sizing and its inclusion of non-printing control codes (such as NUL, BEL, LF, CR, ESC).
Step-by-Step Solution:
Compute capacity: 2^7 = 128 total codes.Printable characters are around 95; control characters commonly counted as 32 in the basic set.Therefore the accurate statement is that ASCII has 128 codes including control characters.Verification / Alternative check:Reference tables list codes 0–31 as control and 32–126 as printable, with 127 as DEL. This aligns with the chosen statement.
Why Other Options Are Wrong:
- subset of EBCDIC: false; EBCDIC is an unrelated 8-bit IBM encoding.
- used only in Western Countries: false; ASCII underpins global protocols.
- version II of ASC Standard: not a recognized description.
- None of the above: incorrect because the correct description is provided.
Common Pitfalls:Confusing ASCII (7-bit) with extended ASCII (8-bit variants) and mixing it with EBCDIC mappings.
Final Answer:has 128 characters, including 32 control characters