The correct answer is (c) Alphanso.
Alphanso is a variety of mango that is grown in India. It is known for its sweet and juicy flesh, and its smooth, thin skin. Alphanso is considered to be one of the best mangoes in the world, and it is often exported to other countries.
Dashahri is another variety of mango that is grown in India. It is known for its large size and its sweet, tangy flavor. Dashahri is not as popular as Alphanso, but it is still a good variety of mango.
Langra is a variety of mango that is grown in India and Pakistan. It is known for its small size and its sweet, sour flavor. Langra is not as popular as Alphanso or Dashahri, but it is still a good variety of mango.
Amrapali is a variety of mango that is grown in India. It is known for its large size and its sweet, juicy flavor. Amrapali is not as popular as Alphanso, but it is still a good variety of mango.
In conclusion, the preferred variety of mango for export is Alphanso. It is a delicious and juicy mango that is known for its high quality.