Recall the definition

Essential amino acids are those amino acids which cannot be synthesized by the human body in sufficient amount and therefore must be obtained from the diet.

List the relevant amino acids from the options

The options are:

• Valine
• Leucine
• Lysine
• Tyrosine

Check each option

• Valine: essential amino acid
• Leucine: essential amino acid
• Lysine: essential amino acid
• Tyrosine: non-essential / conditionally synthesized in the body from phenylalanine

Conclusion

Since Tyrosine can be synthesized in the body (from phenylalanine), it is not an essential amino acid.

Correct option

$\boxed{\text{D: Tyrosine}}$

Comparison with stored correct answer

Stored correct answer is D, which matches the derived answer.