সঠিক উত্তর হলো খ) The equipment is in such poor condition that we have no alternative but to buy new ones.

• No alternative but:
Meaning: If you have no alternative but to do something, you are forced to do something you do not want to do.
Bangla meaning: কোনো বিকল্প নেই শুধুমাত্র এটি ছাড়া।

Example:
- I'm afraid I have no alternative but to ask you to leave.

Structure: "No alternative but + to + infinitive"
অর্থ: একমাত্র উপায় হলো।

Bangla: যন্ত্রপাতির অবস্থা এত খারাপ যে নতুন কেনা ছাড়া আমাদের আর কোনো বিকল্প নেই।

অন্য অপশনগুলো ভুল:

ক) The equipment is in such poor condition that we have no alternative to buy new ones.
- "no alternative"
- Incomplete expression.
- "But" missing করে sentence incomplete থেকে যায়।

গ) The equipment is in such poor condition that we have any alternative except to buy new ones.
- "any alternative except"
- Context এ negative meaning দরকার ("no" দরকার "any" নয়)।
- "Except" এর চেয়ে "but" বেশি appropriate এই construction এ।

ঘ) The equipment is in such poor condition that we have no other alternative to buy new ones.
- "no other alternative"
- Redundant: "alternative" ইতিমধ্যে "other option" বোঝায় "Other" অতিরিক্ত।