The Octal equivalent of the hexadecimal number 100 is _______.

Correct option is A

​$$(100)_{16} \\\text{Binary conversion of hexadecimal number is -} \\1 \rightarrow 0001 \\0 \rightarrow 0000 \\0 \rightarrow 0000 \\(100)_{16} \rightarrow (000100000000)_2 \\\text{To convert binary into octal, we take 3 digits in the group from right side.} \\000 \, 100 \, 000 \, 000 \\\downarrow \, \downarrow \, \downarrow \, \downarrow \\0 \, 4 \, 0 \, 0 \\(100)_{16} = (400)_8$$​​