What is the recommended forest cover for plains and hills according to the National Forest Policy of $1988$?

• A
  $33 \%$ for plains and $67 \%$ for hills
• B
  $67 \%$ for plains and $33 \%$ for hills
• C
  $20 \%$ for plains and $40 \%$ for hills
• D
  $40 \%$ for plains and $20 \%$ for hills