Directions: A part of the sentence is bold. Below are given alternatives to the bold part at (A), (B) and (C) which may improve the sentence. Choose the correct alternative. In case no improvement is needed your answer is (D).

Q:

Although he got home last night is still a mystery to me.

• 1
  How
• 2
  While
• 3
  Since
• 4
  No improvement