Which amino acids were present in twice the amount in the maize hybrids produced in the year 2000 as compared to the pre existing maize hybrids?

Lysine & Tryptophan Valine & Proline Leucine & Threonine Tryptophan & Proline

Lysine & Tryptophan

Lysine & Tryptophan were present in the twice amount in the maize hybrids produced in the year 2000 as compared to the pre existing maize hybrids.