Choose the option which best expresses the given sentence in indirect speech:

I said to Bob, "Can you complete this work by tomorrow?"

I asked Bob whether he could complete that work by the next day.

The correct answer is Option (3) - I asked Bob whether he could complete that work by the next day.

1. Direct Speech: The original sentence is in direct speech: "Can you complete this work by tomorrow?"
2. Indirect Speech: To convert this into indirect speech:
   • The word "Can" changes to "could" in indirect speech.
   • "You" changes to "he" because the question is being asked about Bob (third person).
   • "This" changes to "that" because it's now referring to something previously mentioned.
   • "By tomorrow" changes to "by the next day" to maintain the indirect structure.

Therefore, the correct indirect speech is: "I asked Bob whether he could complete that work by the next day."