What does this traffic sign mean?

What does this sign mean?

• A

  This indicates a dangerous area prone to lightning strikes.

• B

  This indicates an area where power lines cross the road overhead.

  According to the National Technical Standard on Road Traffic Signs QCVN 41:2019, the sign "overhead power cables" is designated as W.239.
  Where power lines cross the road above, sign W.239 must be placed, accompanied by sign W.509a "safe height" below it.
  Sign W.239 is placed on the right side of the road for both directions of traffic, approximately 20-30 meters from the cable location.
  When the safe height is > 5.5m, it is not necessary to place sign W.239, except in cases where the road section has special operating requirements.

Japanese

Source: https://vtcnews.vn/bien-bao-giao-thong-nay-mang-y-nghia-gi-ar857949.html