Identify the poems termed as “pastoral elegies”:
[A] Lycidas
[B] In memory of W.B. Yeats
[C] Adonais
[D] Thyrsis
[E] In memoriam
Choose the most appropriate answer from the options given below:

The correct option is A, C and D only.

A pastoral elegy is a poem that uses the conventions of pastoral poetry—such as depicting the poet and the deceased as shepherds in an idealized, rustic nature setting—to mourn the death of a friend or a significant figure.
Let us analyze the given poems to identify which of them fit this category:

[A] Lycidas: Written by John Milton in 1637, this poem mourns the death of his college friend Edward King, who drowned at sea. Milton adopts the persona of a shepherd mourning a fellow shepherd, making it one of the most famous pastoral elegies in the English language.

[B] In Memory of W.B. Yeats: Written by W. H. Auden in 1939, this is a modern elegy commemorating the death of the Irish poet William Butler Yeats. It does not use the shepherd personas, pastoral landscape, or classical conventions of the pastoral tradition.

[C] Adonais: Written by Percy Bysshe Shelley in 1821, this pastoral elegy mourns the untimely death of the poet John Keats. Shelley uses classical Greek pastoral conventions, presenting Keats as the shepherd Adonais and invoking nature to join in the mourning.

[D] Thyrsis: Written by Matthew Arnold in 1865, this poem commemorates his close friend and fellow poet Arthur Hugh Clough. It is set in the rural countryside around Oxford and follows the pastoral elegy tradition by representing Clough as the shepherd Thyrsis.

[E] In Memoriam A.H.H.: Written by Alfred, Lord Tennyson in 1849, this is a monumental elegiac work mourning the death of his friend Arthur Henry Hallam. While it deals deeply with grief, faith, and philosophy, it is not structured as a pastoral elegy and does not utilize pastoral conventions.

Therefore, only [A] Lycidas, [C] Adonais, and [D] Thyrsis are pastoral elegies.