Choose the best option to complete each of the following questions

Choose the best option to complete each of the following questions:
1, "What's the best way to get around Hoi An town?" - "..."
A, That's useful          B, I suggest walking          C, It's worth seeing          D, Great, thanks
2, Nam: "Congratulations on your success!". Hoa: "..."
A, You're welcome          B, That's very kind of you          C, No, thanks          D, Yes, of course
3, China is ... far the most populated country in the world
A, as          B, by          C, so          D, too