The original answer key here was left blank as None, so under the correction policy we reason to the strongest single option. Three of the four choices, Ewing sarcoma, osteosarcoma and chondrosarcoma, are localised primary tumours of bone. None of them carries any recognised connection to blood sugar levels, so picking any of them would be guessing on no physiological basis. Multiple myeloma stands apart from the trio. It is not a bone-forming tumour but a malignancy of plasma cells that spreads through the marrow and produces wide-ranging systemic and metabolic effects across the body. Of the four options it is the only systemic disease with the kind of broad metabolic footprint that could plausibly be tied to a glucose abnormality, while the bone sarcomas have no such link whatsoever. By elimination and by its systemic nature, multiple myeloma is the only option that can reasonably be defended as the associated condition here.
\[\boxed{\text{Multiple myeloma}}\]