Which of the following roles would support negotiations with an external supplier when planning a...

For low-value, routine purchases, the involvement of The procurement manager (C) and An internal business user (E) is appropriate. The procurement manager brings expertise in supplier engagement, while the internal business user provides insights on specific needs for the productor service. Involving high-level roles, like the CEO or a legal advisor, is unnecessary for routine purchases, as per CIPS guidance on resource alignment in procurement.