The resistivity of iron is$1 \times {10^{ - 7}}\,ohm - m$. The resistance of a iron wire of particular length and thickness is $1\, ohm$. If the length and the diameter of wire both are doubled, then the resistivity in $ohm - m$ will be
  • A$1 \times {10^{ - 7}}$
  • B$2 \times {10^{ - 7}}$
  • C$4 \times {10^{ - 7}}$
  • D$8 \times {10^{ - 7}}$
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