What is the frequency range of microwaves?

• A
  $0.3 \, GHz$ to $300 \, GHz$
• B
  $54 \, MHz$ to $890 \, MHz$
• C
  $3 \, GHz$ to $300 \, GHz$
• D
  $4 \times 10^{14} \, Hz$ to $7 \times 10^{14} \, Hz$