Which sign indicates a dual carriageway?

Which sign indicates a "dual carriageway"?

• A

  Seas 1 and 2

• B

  Seas 1 and 3

• C

  Seas 2 and 3

• D

  Sea 2

  According to the National Technical Standard on Road Traffic Signs QCVN 41:2019, the "dual carriageway" sign (symbol W.235) is used to inform drivers that they are about to enter a two-way road section with a median divider.
  Sign W.235 is installed at the beginning of the road section and in a convenient location for drivers to easily see. This is to ensure that drivers on the road can promptly control their vehicles in accordance with regulations.
  Identifying features: an equilateral triangle with a red border, a yellow background, a black drawing of two arrows pointing in opposite directions, and possibly a dividing line above.

Japanese

Source: https://vtcnews.vn/bien-nao-bao-hieu-duong-doi-ar862005.html