Final answer:
Wes's actions at Miss Trethway's grave are not explicitly detailed in the provided references. A little bunch of lavender daisies was mentioned which could suggest (A) flowers being placed at the grave, but it's not clear that it was done by Wes.
Step-by-step explanation:
The question refers to an event regarding what Wes placed on Miss Trethway's grave. Based on the provided information, we can determine that neither a poem, a rock, nor a photograph was specifically mentioned as an item Wes placed on the grave. Instead, there is a mention of a "little bunch of pale, sweet lavender daisies" found at an unmarked grave, which implies that these may have been placed there as a tribute.
However, this detail comes from Jane rather than Wes. The additional detail in the reference mentions a faded bunch of flowers, but this is in a different context and does not clearly connect to Wes's actions at Miss Trethway's grave.