High alloys steels are preheated up to what temperature?

• A. 350¬¨¬®‚Äö√†√ªC
• B. 400¬¨¬®‚Äö√†√ªC
• C. 450¬¨¬®‚Äö√†√ªC
• D. 500¬¨¬®‚Äö√†√ªC